Measurements and Geometry

Trigonometry - Sine ratio

By the end of the lesson, the learner should be able to:
- Determine the sine of acute angles in a right-angled triangle
- Calculate sine ratios from given measurements
- Connect sine ratio to calculating heights of buildings and trees

- Measure opposite side and hypotenuse in similar triangles
- Calculate ratio of opposite to hypotenuse for angle θ
- Observe that the ratio is constant for the same angle
- Work out sine of angles in various triangles

What is the sine of an angle?

- Mentor Essential Mathematics pg. 69
- Rulers
- Protractors
- Calculators

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Applications of sine ratio

By the end of the lesson, the learner should be able to:
- Apply sine ratio to solve problems
- Calculate sine from real-life situations
- Use sine in determining heights of slides and inclined structures

- Calculate sine of angles formed by ladders and ground
- Work out sine of angles in roof truss designs
- Solve problems involving playground slides
- Present solutions to peers

How is sine ratio applied in real life?

- Mentor Essential Mathematics pg. 71
- Calculators
- Rulers
- Digital resources

- Observation - Oral questions - Written assignments

Measurements and Geometry

Trigonometry - Cosine ratio
Trigonometry - Applications of cosine ratio

By the end of the lesson, the learner should be able to:
- Determine the cosine of acute angles in a right-angled triangle
- Calculate cosine ratios from given measurements
- Apply cosine ratio to navigation and distance calculations

- Measure adjacent side and hypotenuse in similar triangles
- Calculate ratio of adjacent to hypotenuse for angle θ
- Observe that the ratio is constant for the same angle
- Work out cosine of angles in various triangles

What is the cosine of an angle?

- Mentor Essential Mathematics pg. 72
- Rulers
- Protractors
- Calculators
- Mentor Essential Mathematics pg. 74
- Calculators
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Sines and cosines of complementary angles

By the end of the lesson, the learner should be able to:
- Relate sines and cosines of complementary angles
- Use calculator to find sines and cosines of complementary angles
- Apply complementary angle relationships to solving equations

- Discuss meaning of complementary angles
- Use calculator to complete table of sin θ and cos(90°-θ)
- Observe that sin α = cos(90°-α)
- Verify relationship using different angle pairs

What is the relationship between sine and cosine of complementary angles?

- Mentor Essential Mathematics pg. 75
- Scientific calculators
- Reference books
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Solving equations involving complementary angles

By the end of the lesson, the learner should be able to:
- Solve equations involving sines and cosines of complementary angles
- Apply the relationship sin θ = cos(90°-θ)
- Use complementary angle properties in practical calculations

- Solve equations like sin θ = cos 40°
- Work out problems involving sin(x-55) = cos x
- Apply complementary angle relationships
- Share solutions with peers

How do we solve equations involving complementary angles?

- Mentor Essential Mathematics pg. 76
- Scientific calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Trigonometry - Making a clinometer

By the end of the lesson, the learner should be able to:
- Make a simple clinometer using locally available materials
- Use the clinometer to measure angles
- Apply clinometer skills to measuring heights of buildings and trees

- Gather manila paper, protractor, string and weight
- Trace protractor's curved edge and mark degrees
- Attach straw along straight edge
- Tie string with weight at centre point

How do we make and use a clinometer?

- Mentor Essential Mathematics pg. 77
- Manila paper
- Blackboard protractor
- String and weight

- Observation - Practical work - Oral questions

Measurements and Geometry

Trigonometry - Angle of elevation

By the end of the lesson, the learner should be able to:
- Apply trigonometric ratios to angles of elevation
- Calculate heights using angles of elevation
- Use angle of elevation in determining heights of flagpoles, trees and buildings

- Use clinometer to measure angle of elevation of tall objects
- Measure horizontal distance from object
- Apply trigonometric ratios to calculate heights
- Compare calculated heights with actual measurements

How do we use angles of elevation to find heights?

- Mentor Essential Mathematics pg. 79
- Clinometers
- Tape measures
- Calculators

- Observation - Practical work - Written tests

Measurements and Geometry

Trigonometry - Angle of elevation

By the end of the lesson, the learner should be able to:
- Apply trigonometric ratios to angles of elevation
- Calculate heights using angles of elevation
- Use angle of elevation in determining heights of flagpoles, trees and buildings

- Use clinometer to measure angle of elevation of tall objects
- Measure horizontal distance from object
- Apply trigonometric ratios to calculate heights
- Compare calculated heights with actual measurements

How do we use angles of elevation to find heights?

- Mentor Essential Mathematics pg. 79
- Clinometers
- Tape measures
- Calculators

- Observation - Practical work - Written tests

Measurements and Geometry

Trigonometry - Angle of elevation

By the end of the lesson, the learner should be able to:
- Apply trigonometric ratios to angles of elevation
- Calculate heights using angles of elevation
- Use angle of elevation in determining heights of flagpoles, trees and buildings

- Use clinometer to measure angle of elevation of tall objects
- Measure horizontal distance from object
- Apply trigonometric ratios to calculate heights
- Compare calculated heights with actual measurements

How do we use angles of elevation to find heights?

- Mentor Essential Mathematics pg. 79
- Clinometers
- Tape measures
- Calculators

- Observation - Practical work - Written tests

Measurements and Geometry

Trigonometry - Problems on angle of elevation

By the end of the lesson, the learner should be able to:
- Solve problems involving angles of elevation
- Apply trigonometric ratios to real-life situations
- Calculate heights of towers, monuments and tall structures

- Draw sketches from word problems
- Identify given information and required values
- Apply appropriate trigonometric ratios
- Calculate heights and distances

How do we solve problems on angles of elevation?

- Mentor Essential Mathematics pg. 80
- Calculators
- Rulers
- Exercise books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Trigonometry - Angle of depression

By the end of the lesson, the learner should be able to:
- Apply trigonometric ratios to angles of depression
- Calculate distances using angles of depression
- Use angle of depression in aviation and marine navigation

- Discuss meaning of angle of depression
- Draw diagrams showing angles of depression
- Apply trigonometric ratios to find distances
- Solve problems involving observers on cliffs and buildings

How do we use angles of depression to find distances?

- Mentor Essential Mathematics pg. 80
- Calculators
- Rulers
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Angle of depression

By the end of the lesson, the learner should be able to:
- Apply trigonometric ratios to angles of depression
- Calculate distances using angles of depression
- Use angle of depression in aviation and marine navigation

- Discuss meaning of angle of depression
- Draw diagrams showing angles of depression
- Apply trigonometric ratios to find distances
- Solve problems involving observers on cliffs and buildings

How do we use angles of depression to find distances?

- Mentor Essential Mathematics pg. 80
- Calculators
- Rulers
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Application in real life situations

By the end of the lesson, the learner should be able to:
- Solve combined problems on angles of elevation and depression
- Apply trigonometry to various real-life scenarios
- Use trigonometry in determining distances between ships, aircraft heights and building measurements

- Solve problems involving two ships viewed from cliff
- Calculate distances and heights in combined scenarios
- Use digital resources to explore more applications
- Present solutions to class

How is trigonometry used in real life?

- Mentor Essential Mathematics pg. 81
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Trigonometry - Application in real life situations

By the end of the lesson, the learner should be able to:
- Solve combined problems on angles of elevation and depression
- Apply trigonometry to various real-life scenarios
- Use trigonometry in determining distances between ships, aircraft heights and building measurements

- Solve problems involving two ships viewed from cliff
- Calculate distances and heights in combined scenarios
- Use digital resources to explore more applications
- Present solutions to class

How is trigonometry used in real life?

- Mentor Essential Mathematics pg. 81
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Area of triangle given two sides and an included angle

By the end of the lesson, the learner should be able to:
- Compute area of a triangle given two sides and an included acute angle
- Apply the formula Area = ½ab sin C
- Calculate areas of triangular flowerbeds, gardens and plots

- Identify triangular shapes from patterns in mats and frames
- Measure two sides and the included angle
- Calculate area using formula ½ab sin C
- Share work with classmates

How do we find the area of a triangle given two sides and an included angle?

- Mentor Essential Mathematics pg. 84
- Rulers
- Protractors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Problems on area of triangle

By the end of the lesson, the learner should be able to:
- Solve problems on area of triangles using ½ab sin C
- Find unknown sides or angles given the area
- Apply triangle area calculations to land surveying and construction

- Work out areas of triangular kitchen gardens
- Calculate areas of equilateral triangular seedbeds
- Solve for unknown angles when area is given
- Discuss applications in real life

How do we solve problems involving area of triangles?

- Mentor Essential Mathematics pg. 85
- Calculators
- Rulers
- Exercise books

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Heron's Formula
Area of Polygons - Problems using Heron's Formula

By the end of the lesson, the learner should be able to:
- Determine the area of a triangle given three sides using Heron's Formula
- Calculate semi-perimeter of triangles
- Apply Heron's formula to irregular triangular plots and badges

- Draw right-angled triangle with given measurements
- Calculate perimeter and semi-perimeter
- Apply Heron's formula: √[s(s-a)(s-b)(s-c)]
- Compare with area calculated using other methods

How do we find the area of a triangle using Heron's Formula?

- Mentor Essential Mathematics pg. 86
- Calculators
- Rulers
- Scientific calculators
- Mentor Essential Mathematics pg. 87
- Exercise books
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Area of a rhombus

By the end of the lesson, the learner should be able to:
- Determine the area of a rhombus given the diagonals
- Apply the formula Area = ½ × d₁ × d₂
- Calculate areas of rhombus-shaped tiles, kites and floor patterns

- Draw rhombus and measure diagonals
- Calculate areas of triangles formed by diagonals
- Add areas to get total area of rhombus
- Verify using formula ½ × d₁ × d₂

How do we find the area of a rhombus?

- Mentor Essential Mathematics pg. 88
- Rulers
- Protractors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Area of rhombus given side and angle

By the end of the lesson, the learner should be able to:
- Calculate area of rhombus given side and included angle
- Apply the formula Area = a² sin θ
- Use rhombus area calculations for badges, logos and decorations

- Draw rhombus-shaped badge with given side and angle
- Calculate lengths of diagonals using trigonometry
- Work out area using ½ × d₁ × d₂
- Verify using formula a² sin θ

How do we find area of rhombus given side and angle?

- Mentor Essential Mathematics pg. 89
- Calculators
- Rulers
- Protractors

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Area of a parallelogram

By the end of the lesson, the learner should be able to:
- Determine the area of a parallelogram
- Apply the formula Area = base × perpendicular height
- Calculate areas of parallelogram-shaped solar panels and floor plans

- Draw parallelogram with given dimensions
- Calculate perpendicular height using trigonometry
- Apply formula: base × perpendicular height
- Work out areas of various parallelograms

How do we find the area of a parallelogram?

- Mentor Essential Mathematics pg. 92
- Rulers
- Protractors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Area of parallelogram using ab sin θ

By the end of the lesson, the learner should be able to:
- Calculate area of parallelogram using ab sin θ
- Solve problems involving parallelograms
- Apply parallelogram area to kitchen floor designs and glass panels

- Calculate areas of decorative stones shaped as parallelograms
- Work out areas of kitchen floor plans
- Find angles when area is given
- Share solutions with peers

How do we apply parallelogram area in real life?

- Mentor Essential Mathematics pg. 94
- Calculators
- Rulers
- Exercise books

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Area of a regular pentagon

By the end of the lesson, the learner should be able to:
- Determine the area of a regular pentagon
- Divide pentagon into triangles and calculate total area
- Apply pentagon area to flower bed designs and pizza box lids

- Draw regular pentagon and divide into 5 triangles
- Measure radius from centre to vertex
- Calculate area of one triangle
- Multiply by 5 to get total area

How do we find the area of a regular pentagon?

- Mentor Essential Mathematics pg. 95
- Rulers
- Protractors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Problems on area of pentagon

By the end of the lesson, the learner should be able to:
- Solve problems on area of regular pentagons
- Calculate areas of pentagon-shaped objects
- Apply pentagon area to trampoline covers and decorative designs

- Calculate area of pentagon-shaped flower beds
- Work out area of pizza box lids
- Solve problems involving pentagon-shaped objects
- Present solutions to class

How is area of pentagon applied in real life?

- Mentor Essential Mathematics pg. 97
- Calculators
- Exercise books
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Area of a regular hexagon

By the end of the lesson, the learner should be able to:
- Determine the area of a regular hexagon
- Divide hexagon into 6 triangles and calculate total area
- Apply hexagon area to floor tiling and road sign designs

- Draw regular hexagon and divide into 6 triangles
- Measure radius from centre to vertex
- Calculate area of one triangle
- Multiply by 6 to get total area

How do we find the area of a regular hexagon?

- Mentor Essential Mathematics pg. 96
- Rulers
- Protractors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Application in real life situations

By the end of the lesson, the learner should be able to:
- Apply areas of polygons in real-life situations
- Solve combined problems on areas of polygons
- Use polygon areas in calculating material costs and backyard coverage

- Calculate areas of hexagonal tile sections
- Work out total area of backyards covered with hexagonal blocks
- Determine cost of materials for polygon-shaped items
- Discuss applications in day-to-day life

How are areas of polygons useful in real life?

- Mentor Essential Mathematics pg. 98
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Application in real life situations

By the end of the lesson, the learner should be able to:
- Apply areas of polygons in real-life situations
- Solve combined problems on areas of polygons
- Use polygon areas in calculating material costs and backyard coverage

- Calculate areas of hexagonal tile sections
- Work out total area of backyards covered with hexagonal blocks
- Determine cost of materials for polygon-shaped items
- Discuss applications in day-to-day life

How are areas of polygons useful in real life?

- Mentor Essential Mathematics pg. 98
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Application in real life situations

By the end of the lesson, the learner should be able to:
- Apply areas of polygons in real-life situations
- Solve combined problems on areas of polygons
- Use polygon areas in calculating material costs and backyard coverage

- Calculate areas of hexagonal tile sections
- Work out total area of backyards covered with hexagonal blocks
- Determine cost of materials for polygon-shaped items
- Discuss applications in day-to-day life

How are areas of polygons useful in real life?

- Mentor Essential Mathematics pg. 98
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of a Part of a Circle - Area of a sector

By the end of the lesson, the learner should be able to:
- Determine the area of a sector of a circle
- Apply the formula Area = θ/360 × πr²
- Calculate areas of hand-fans, sprinkler coverage and cake toppings

- Draw circle and mark sector AOB
- Measure radius and angle subtended at centre
- Apply formula θ/360 × πr²
- Share findings with classmates

How do we find the area of a sector?

- Mentor Essential Mathematics pg. 101
- Compasses
- Protractors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of a Part of a Circle - Problems on area of sector

By the end of the lesson, the learner should be able to:
- Solve problems on area of sectors
- Find radius or angle when area is given
- Apply sector area to garden sprinklers and billboard sections

- Calculate area of sector-shaped artisan designs
- Work out angle when area and radius are given
- Determine radius when area and angle are given
- Present solutions to peers

How do we solve problems involving sectors?

- Mentor Essential Mathematics pg. 102
- Calculators
- Rulers
- Exercise books

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of a Part of a Circle - Area of a segment
Area of a Part of a Circle - Problems on area of segment

By the end of the lesson, the learner should be able to:
- Determine the area of a segment of a circle
- Apply the formula: Area of sector - Area of triangle
- Calculate areas of parking lots, decorations and glass windows

- Draw circle with sector and identify segment
- Calculate area of sector using θ/360 × πr²
- Calculate area of triangle using ½r² sin θ
- Subtract to get area of segment

How do we find the area of a segment?

- Mentor Essential Mathematics pg. 103
- Compasses
- Protractors
- Calculators
- Mentor Essential Mathematics pg. 105
- Calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of a Part of a Circle - Area swept by gate

By the end of the lesson, the learner should be able to:
- Apply area of sector to find area swept by rotating objects
- Calculate area covered by opening gates and doors
- Use sector area in clock hand problems and fan blade designs

- Observe area covered by gate when it opens
- Measure angle of rotation and length of gate
- Calculate area swept using sector formula
- Discuss other applications

How do we calculate area swept by rotating objects?

- Mentor Essential Mathematics pg. 107
- Tape measures
- Protractors
- Calculators

- Observation - Practical work - Written assignments

Measurements and Geometry

Area of a Part of a Circle - Problems on curved paths and decorations

By the end of the lesson, the learner should be able to:
- Calculate areas of curved paths and decorations
- Solve problems on sector and segment areas
- Apply concepts to fan blade designs and table cloth decorations

- Calculate area of curved paths in school compound
- Work out area of decorations on table cloths
- Solve problems on fanning papers
- Present solutions to class

How are areas of parts of circles applied in design?

- Mentor Essential Mathematics pg. 108
- Calculators
- Rulers
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of a Part of a Circle - Clock and sprinkler problems

By the end of the lesson, the learner should be able to:
- Solve problems involving clock hands and sprinklers
- Calculate area covered by minute and hour hands
- Apply sector area to irrigation system design and garden planning

- Calculate area swept by minute hand of clock
- Work out area covered by hour hand moving through 180°
- Determine area watered by rotating sprinklers
- Discuss efficient irrigation systems

How do we apply sector area to clocks and sprinklers?

- Mentor Essential Mathematics pg. 110
- Calculators
- Clocks
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of a Part of a Circle - Combined problems

By the end of the lesson, the learner should be able to:
- Solve combined problems on sectors and segments
- Apply area of parts of circles in various contexts
- Use concepts in calculating metal sheet areas and flower garden segments

- Calculate area of metal sheet in segment shape
- Work out area of flower segments in circular gardens
- Solve problems on staffroom doors and gates
- Review all concepts on area of parts of circles

Where do we use area of part of a circle in real life?

- Mentor Essential Mathematics pg. 111
- Calculators
- Exercise books
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Surface Area of Solids - Nets of cones

By the end of the lesson, the learner should be able to:
- Identify the net of a cone
- Recognize parts of a cone net (sector and circular base)
- Relate cone shapes to everyday objects like ice cream cones and traffic cones

- Collect common solids with cone shapes from the environment
- Make model of closed cone using manila paper
- Open the cone along its slant to get net
- Identify sector and circular base in the net

What shapes make up the net of a cone?

- Mentor Essential Mathematics pg. 112
- Manila paper
- Scissors
- Cone-shaped objects

- Observation - Oral questions - Written assignments

Measurements and Geometry

Surface Area of Solids - Surface area of a cone from its net

By the end of the lesson, the learner should be able to:
- Determine surface area of cones from nets
- Calculate area of sector and circular base
- Apply cone surface area to calculating material for making party hats and funnels

- Measure angle, radius of sector and radius of circular base
- Calculate area of sector using θ/360 × πr²
- Calculate area of circular base using πr²
- Add to get total surface area

How do we find the surface area of a cone from its net?

- Mentor Essential Mathematics pg. 113
- Cone nets
- Protractors
- Calculators

- Observation - Oral questions - Written tests

Measurements and Geometry

Surface Area of Solids - Surface area of cone using formula
Surface Area of Solids - Nets of pyramids

By the end of the lesson, the learner should be able to:
- Calculate surface area of cones using πrl + πr²
- Solve problems on surface area of cones
- Use cone surface area in designing Christmas hats, filter papers and decorative cones

- Apply formula: Curved surface area = πrl
- Apply formula: Total surface area = πrl + πr²
- Calculate surface area of Christmas hats
- Solve problems on filter paper cones

How do we calculate surface area of a cone using the formula?

- Mentor Essential Mathematics pg. 114
- Calculators
- Exercise books
- Reference books
- Mentor Essential Mathematics pg. 115
- Manila paper
- Scissors
- Rulers

- Observation - Oral questions - Written assignments

Measurements and Geometry

Surface Area of Solids - Surface area of square-based pyramid

By the end of the lesson, the learner should be able to:
- Determine surface area of square-based pyramids from nets
- Calculate area of square base and triangular faces
- Apply to gift box designs, glass covers for skylights and decorative items

- Sketch net of square-based pyramid
- Calculate area of square base
- Calculate area of four identical triangular faces
- Add to get total surface area

How do we find surface area of a square-based pyramid?

- Mentor Essential Mathematics pg. 116
- Graph paper
- Calculators
- Rulers

- Observation - Oral questions - Written assignments

Measurements and Geometry

Surface Area of Solids - Surface area of rectangular-based pyramid

By the end of the lesson, the learner should be able to:
- Determine surface area of rectangular-based pyramids
- Calculate areas of different pairs of triangular faces
- Apply to camping tent designs, monument construction and roof structures

- Draw net of rectangular-based pyramid
- Calculate area of rectangular base
- Work out areas of two pairs of triangular faces
- Add all areas to get total surface area

How do we find surface area of a rectangular-based pyramid?

- Mentor Essential Mathematics pg. 117
- Graph paper
- Calculators
- Rulers

- Observation - Oral questions - Written tests

Measurements and Geometry

Surface Area of Solids - Surface area of a sphere

By the end of the lesson, the learner should be able to:
- Calculate the surface area of a sphere
- Apply the formula 4πr²
- Use sphere surface area in calculating material for balls, globes and decorative spheres

- Collect spherical objects (soccer balls, marbles, oranges)
- Estimate and record radius of each object
- Calculate surface area using formula 4πr²
- Share work with other groups

How do we find the surface area of a sphere?

- Mentor Essential Mathematics pg. 120
- Spherical objects
- Rulers
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Surface Area of Solids - Surface area of a hemisphere

By the end of the lesson, the learner should be able to:
- Calculate the surface area of a solid hemisphere
- Apply the formula 3πr²
- Use hemisphere surface area in calculating material for bowls, domes and decorative half-spheres

- Cut spherical object (orange) into two equal halves
- Estimate radius of hemisphere
- Calculate curved surface area (2πr²)
- Add circular base area to get total (3πr²)

How do we find the surface area of a hemisphere?

- Mentor Essential Mathematics pg. 121
- Oranges
- Knives
- Calculators

- Observation - Practical work - Written tests

Measurements and Geometry

Surface Area of Solids - Surface area of frustum of a cone

By the end of the lesson, the learner should be able to:
- Determine surface area of frustum of a cone
- Identify top radius, bottom radius and slant height
- Apply frustum surface area to bucket designs and lampshade construction

- Make model of cone and cut parallel to base to form frustum
- Identify top radius (r), bottom radius (R) and slant height (L)
- Calculate lateral surface area: πL(R + r)
- Discuss formula for total surface area

How do we find surface area of a frustum of a cone?

- Mentor Essential Mathematics pg. 122
- Manila paper
- Scissors
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Surface Area of Solids - Problems on frustum of a cone

By the end of the lesson, the learner should be able to:
- Solve problems on surface area of frustums of cones
- Calculate surface areas of open and closed frustums
- Apply to coffee cups, loudspeaker diaphragms and chemical storage buckets

- Calculate total surface area: πL(R+r) + πR² + πr²
- Work out surface area of open-top coffee cups
- Calculate curved surface area of loudspeaker diaphragms
- Solve problems on buckets storing chemicals

How do we solve problems on frustum surface area?

- Mentor Essential Mathematics pg. 124
- Calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Surface Area of Solids - Surface area of frustum of a pyramid

By the end of the lesson, the learner should be able to:
- Determine surface area of frustum of a square-based pyramid
- Calculate lateral surface area using ½(P₁ + P₂) × L
- Apply to lampshade designs, water tanks and display stands

- Make model of pyramid and cut parallel to base
- Identify top perimeter (P₁), bottom perimeter (P₂) and slant height (L)
- Calculate lateral surface area: ½(P₁ + P₂) × L
- Add areas of top and bottom to get total surface area

How do we find surface area of a frustum of a pyramid?

- Mentor Essential Mathematics pg. 125
- Manila paper
- Scissors
- Calculators

- Observation - Practical work - Written assignments

Measurements and Geometry

Surface Area of Solids - Surface area of frustum of a pyramid

By the end of the lesson, the learner should be able to:
- Determine surface area of frustum of a square-based pyramid
- Calculate lateral surface area using ½(P₁ + P₂) × L
- Apply to lampshade designs, water tanks and display stands

- Make model of pyramid and cut parallel to base
- Identify top perimeter (P₁), bottom perimeter (P₂) and slant height (L)
- Calculate lateral surface area: ½(P₁ + P₂) × L
- Add areas of top and bottom to get total surface area

How do we find surface area of a frustum of a pyramid?

- Mentor Essential Mathematics pg. 125
- Manila paper
- Scissors
- Calculators

- Observation - Practical work - Written assignments

Measurements and Geometry

Surface Area of Solids - Problems on frustum of a pyramid

By the end of the lesson, the learner should be able to:
- Solve problems on surface area of frustums of pyramids
- Calculate surface area of rectangular-based pyramid frustums
- Apply to hollow lampshades, counter designs, statue stands and open water tanks

- Calculate areas of trapezoidal faces for rectangular-based frustums
- Work out surface area of hollow lampshades (lateral only)
- Solve problems on counters and statue stands
- Determine material needed for multiple lampshades

How are frustums of pyramids used in real life?

- Mentor Essential Mathematics pg. 127
- Calculators
- Exercise books
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Surface Area of Solids - Problems on frustum of a pyramid

By the end of the lesson, the learner should be able to:
- Solve problems on surface area of frustums of pyramids
- Calculate surface area of rectangular-based pyramid frustums
- Apply to hollow lampshades, counter designs, statue stands and open water tanks

- Calculate areas of trapezoidal faces for rectangular-based frustums
- Work out surface area of hollow lampshades (lateral only)
- Solve problems on counters and statue stands
- Determine material needed for multiple lampshades

How are frustums of pyramids used in real life?

- Mentor Essential Mathematics pg. 127
- Calculators
- Exercise books
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Volume and Capacity - Volume of a cone

By the end of the lesson, the learner should be able to:
- Determine the volume of a cone
- Apply the formula V = ⅓πr²h
- Relate cone volume to measuring ingredients and ice cream scoops

- Make models of cone and cylinder with equal base radius and height
- Fill cone with sand and empty into cylinder
- Count number of cones needed to fill cylinder
- Establish relationship between cone and cylinder volumes

What is the relationship between volume of a cone and cylinder?

- Mentor Essential Mathematics pg. 132
- Manila paper
- Sand
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Problems on volume of cones

By the end of the lesson, the learner should be able to:
- Calculate volume of cones given dimensions
- Determine capacity of cone-shaped containers
- Apply cone volume to funnel designs and conical flasks in laboratories

- Calculate volume of cone-shaped containers
- Convert volume to capacity in litres
- Work out radius or height when volume is given
- Solve problems on ice cream cones and funnels

How do we calculate the capacity of a cone?

- Mentor Essential Mathematics pg. 133
- Calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Volume and Capacity - Volume of cone given slant height
Volume and Capacity - Volume of a pyramid

By the end of the lesson, the learner should be able to:
- Calculate volume of cone given slant height and radius
- Use Pythagoras theorem to find vertical height
- Apply to cone-shaped ornaments and decorative items

- Draw cone with slant height and radius labelled
- Apply Pythagorean relationship to find vertical height
- Calculate volume using V = ⅓πr²h
- Solve problems involving slant heights

How do we find volume when slant height is given?

- Mentor Essential Mathematics pg. 134
- Calculators
- Rulers
- Exercise books
- Mentor Essential Mathematics pg. 135
- Pyramid models
- Calculators

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Problems on volume of pyramids

By the end of the lesson, the learner should be able to:
- Solve problems on volume of pyramids
- Calculate capacity of pyramid-shaped containers
- Apply pyramid volume to water tanks and yoghurt packaging boxes

- Calculate volume of underground water tanks
- Work out capacity of pyramid-shaped gift boxes
- Determine dimensions when volume is given
- Share solutions with peers

How is pyramid volume applied in real life?

- Mentor Essential Mathematics pg. 136
- Calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Volume of frustum of a cone

By the end of the lesson, the learner should be able to:
- Determine volume of frustum of a cone
- Calculate volume by subtracting smaller cone from larger cone
- Apply to bucket designs and lampshade constructions

- Make model of cone and cut parallel to base
- Measure radii and heights of both cones
- Calculate volumes of original and cut-off cones
- Subtract to get volume of frustum

How do we find volume of a frustum of a cone?

- Mentor Essential Mathematics pg. 138
- Manila paper
- Scissors
- Calculators

- Observation - Practical work - Written tests

Measurements and Geometry

Volume and Capacity - Problems on frustum of a cone

By the end of the lesson, the learner should be able to:
- Solve problems on volume of frustum of a cone
- Calculate capacity of frustum-shaped containers
- Apply to traditional cooking pots, water collection containers and metallic buckets

- Calculate volume of rainwater collection containers
- Work out capacity of traditional cooking pots
- Determine volume of frustum-shaped drinking water buckets
- Convert volumes to litres and millilitres

How do we calculate capacity of frustum-shaped containers?

- Mentor Essential Mathematics pg. 140
- Calculators
- Exercise books
- Digital resources

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Volume of frustum of a pyramid

By the end of the lesson, the learner should be able to:
- Determine volume of frustum of a pyramid
- Calculate volume by subtracting smaller pyramid from larger pyramid
- Apply to water storage tanks and traditional basket designs

- Make model of pyramid and cut parallel to base
- Measure dimensions of original and cut-off pyramids
- Calculate volumes of both pyramids
- Subtract to get volume of frustum

How do we find volume of a frustum of a pyramid?

- Mentor Essential Mathematics pg. 142
- Manila paper
- Scissors
- Calculators

- Observation - Practical work - Written tests

Measurements and Geometry

Volume and Capacity - Problems on frustum of a pyramid

By the end of the lesson, the learner should be able to:
- Solve problems on volume of frustum of a pyramid
- Calculate capacity of pyramid frustum containers
- Apply to water troughs, flower vases and lunch boxes

- Calculate volume of water troughs cut from pyramids
- Work out capacity of traditional woven baskets
- Determine volume of flower vases and lunch boxes
- Convert to litres and millilitres

How is frustum of pyramid volume applied?

- Mentor Essential Mathematics pg. 144
- Calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Volume of composite solids

By the end of the lesson, the learner should be able to:
- Calculate volume of composite solids
- Combine volumes of different shapes
- Apply to school podiums, water reservoirs and combined storage structures

- Identify composite solids made of frustums and other shapes
- Break down into simpler shapes
- Calculate volume of each part
- Add to get total volume

How do we find volume of composite solids?

- Mentor Essential Mathematics pg. 145
- Calculators
- Models of solids
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Volume and Capacity - Volume of composite solids

By the end of the lesson, the learner should be able to:
- Calculate volume of composite solids
- Combine volumes of different shapes
- Apply to school podiums, water reservoirs and combined storage structures

- Identify composite solids made of frustums and other shapes
- Break down into simpler shapes
- Calculate volume of each part
- Add to get total volume

How do we find volume of composite solids?

- Mentor Essential Mathematics pg. 145
- Calculators
- Models of solids
- Digital resources

- Observation - Oral questions - Written tests

Measurements and Geometry

Volume and Capacity - Capacity problems

By the end of the lesson, the learner should be able to:
- Convert between volume and capacity units
- Solve problems involving litres and millilitres
- Apply to water storage, milk packaging and fuel tank capacities

- Convert cubic metres to litres
- Convert cubic centimetres to millilitres
- Calculate capacity of various containers
- Solve real-life problems on water and fuel storage

Why is the knowledge of volume and capacity useful?

- Mentor Essential Mathematics pg. 146
- Calculators
- Containers
- Exercise books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Combined problems

By the end of the lesson, the learner should be able to:
- Solve combined problems on volume and capacity
- Apply volume concepts to various real-life situations
- Use volume and capacity in water trough designs for livestock and reservoir planning

- Solve mixed problems on cones, pyramids and frustums
- Calculate capacity of mugs, buckets and tanks
- Work out dimensions when capacity is given
- Review all concepts on volume and capacity

How do we apply volume and capacity in daily life?

- Mentor Essential Mathematics pg. 147
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Volume and Capacity - Combined problems

By the end of the lesson, the learner should be able to:
- Solve combined problems on volume and capacity
- Apply volume concepts to various real-life situations
- Use volume and capacity in water trough designs for livestock and reservoir planning

- Solve mixed problems on cones, pyramids and frustums
- Calculate capacity of mugs, buckets and tanks
- Work out dimensions when capacity is given
- Review all concepts on volume and capacity

How do we apply volume and capacity in daily life?

- Mentor Essential Mathematics pg. 147
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written tests