Measurements and Geometry

Similarity and Enlargement - Properties of similar figures

By the end of the lesson, the learner should be able to:

- Identify properties of similar figures
- Compare corresponding sides and angles of similar figures
- Relate similarity to real life objects like photographs and maps

- Collect objects from the environment and sort similar objects together
- Measure corresponding sides of similar triangles and determine ratios
- Measure corresponding angles of similar figures
- Discuss reasons why objects are considered similar

How do we identify similar figures in our environment?

- Mentor Essential Mathematics pg. 31
- Similar objects (containers, shapes)
- Rulers and protractors
- Digital resources

- Observation - Oral questions - Written assignments

Measurements and Geometry

Similarity and Enlargement - Properties of similar figures
Similarity and Enlargement - Centre of enlargement and linear scale factor

By the end of the lesson, the learner should be able to:

- Determine whether given figures are similar
- Calculate ratios of corresponding sides
- Connect similar figures to everyday items like photo frames and tiles

- Work out ratios of corresponding sides of triangles
- Use protractor to measure corresponding angles
- Determine if rectangles are similar by comparing ratios
- Share findings with classmates

What conditions must be met for two figures to be similar?

- Mentor Essential Mathematics pg. 33
- Protractors
- Rulers
- Cut-outs of similar shapes
- Mentor Essential Mathematics pg. 37
- Plain paper
- Pencils

- Observation - Oral questions - Written tests

Measurements and Geometry

Similarity and Enlargement - Linear scale factor
Similarity and Enlargement - Drawing images under enlargement

By the end of the lesson, the learner should be able to:

- Determine the linear scale factor of similar figures
- Calculate linear scale factor from given measurements
- Apply linear scale factor concepts to map reading and architectural drawings

- Measure distances from centre of enlargement to object and image
- Calculate ratio of image distance to object distance
- Work out linear scale factors for different figures
- Discuss applications of scale factors

What is the relationship between object and image distances?

- Mentor Essential Mathematics pg. 38
- Rulers
- Graph paper
- Calculators
- Mentor Essential Mathematics pg. 40
- Geometrical instruments

- Observation - Oral questions - Written tests

Measurements and Geometry

Similarity and Enlargement - Drawing images on Cartesian plane
Similarity and Enlargement - Area scale factor

By the end of the lesson, the learner should be able to:

- Draw images on Cartesian plane given scale factor and centre
- Plot coordinates of image points
- Apply enlargement skills to graphic design and scaling images

- Plot objects on Cartesian plane
- Calculate image coordinates using scale factor
- Draw images under enlargement with different centres
- Verify accuracy of constructions

How do we enlarge figures on the Cartesian plane?

- Mentor Essential Mathematics pg. 41
- Graph paper
- Rulers
- Pencils
- Mentor Essential Mathematics pg. 42
- Calculators
- Rulers

- Observation - Practical work - Written tests

Measurements and Geometry

Similarity and Enlargement - Area scale factor calculations
Similarity and Enlargement - Volume scale factor

By the end of the lesson, the learner should be able to:

- Calculate area scale factor from given measurements
- Apply area scale factor formula
- Use area scale factor in calculating painting and carpeting costs

- Work out area scale factors for various similar figures
- Solve problems involving area scale factor
- Apply area scale factor to real-life scenarios
- Share solutions with peers

How is area scale factor applied in real life?

- Mentor Essential Mathematics pg. 44
- Calculators
- Rulers
- Digital resources
- Mentor Essential Mathematics pg. 43
- Similar containers
- Calculators

- Observation - Oral questions - Written tests

Measurements and Geometry

Similarity and Enlargement - Relating linear, area and volume scale factors

By the end of the lesson, the learner should be able to:

- Relate linear scale factor to area and volume scale factors
- Convert between different scale factors
- Apply scale factor relationships to model making and engineering

- Make similar cylinders of different sizes
- Calculate ratios of heights, areas, and volumes
- Compare the three ratios and establish relationships
- Solve problems involving all three scale factors

How are the three scale factors related?

- Mentor Essential Mathematics pg. 45
- Manila paper
- Calculators
- Scissors

- Observation - Oral questions - Written tests

Measurements and Geometry

Similarity and Enlargement - Application to area

By the end of the lesson, the learner should be able to:

- Apply linear scale factor to find areas of similar figures
- Solve problems on area using scale factors
- Connect similarity concepts to architectural blueprints and scale models

- Calculate areas of similar figures using scale factors
- Solve word problems involving area scale factor
- Use digital devices to explore applications
- Present solutions to peers

How do we apply area scale factor to solve problems?

- Mentor Essential Mathematics pg. 46
- Calculators
- Digital resources
- Reference books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Similarity and Enlargement - Application to volume
Reflection - Lines of symmetry in plane figures

By the end of the lesson, the learner should be able to:

- Apply linear scale factor to find volumes of similar objects
- Solve problems on volume using scale factors
- Use similarity in estimating storage capacities and tank volumes

- Calculate volumes of similar solids using scale factors
- Solve word problems involving volume scale factor
- Complete project on making similar containers
- Document processes and take pictures

How do we apply volume scale factor to solve problems?

- Mentor Essential Mathematics pg. 47
- Calculators
- Manila paper
- Locally available materials
- Mentor Essential Mathematics pg. 50
- Paper cut-outs
- Scissors
- Various 2D objects

- Observation - Project assessment - Written tests

Measurements and Geometry

Reflection - Lines of symmetry in regular polygons
Reflection - Properties of reflection

By the end of the lesson, the learner should be able to:

- Determine lines of symmetry in regular polygons
- State that regular polygons have lines of symmetry equal to number of sides
- Connect symmetry to design patterns in fabric and architecture

- Draw regular polygons and identify lines of symmetry
- Trace diagrams and draw lines of symmetry
- State number of lines of symmetry for various alphabets
- Discuss patterns observed

What is the relationship between sides and lines of symmetry in regular polygons?

- Mentor Essential Mathematics pg. 52
- Rulers
- Protractors
- Plain paper
- Mentor Essential Mathematics pg. 53
- Plane mirrors

- Observation - Oral questions - Written tests

Measurements and Geometry

Reflection - Drawing images given object and mirror line
Reflection - Reflection along x = 0

By the end of the lesson, the learner should be able to:

- Draw an image given an object and mirror line on a plane surface
- Construct perpendicular lines to locate image points
- Apply reflection skills to understanding kaleidoscopes and periscopes

- Trace figures and mirror lines on plain paper
- Construct perpendicular lines from vertices to mirror line
- Measure equal distances on opposite side of mirror line
- Join image points to form reflected image

How do we draw the image of an object after reflection?

- Mentor Essential Mathematics pg. 54
- Plain paper
- Rulers
- Set squares
- Mentor Essential Mathematics pg. 56
- Graph paper
- Pencils

- Observation - Practical work - Written tests

Measurements and Geometry

Reflection - Reflection along y = 0
Reflection - Reflection along y = x

By the end of the lesson, the learner should be able to:

- Draw an image after reflection along the line y = 0
- Determine coordinates of image points when reflected along x-axis
- Apply reflection concepts to architectural symmetry and graphic design

- Plot squares and rectangles on Cartesian plane
- Reflect shapes along line y = 0
- Compare coordinates before and after reflection
- Discuss the transformation rule for y = 0 reflection

What happens to coordinates when reflecting along y = 0?

- Mentor Essential Mathematics pg. 58
- Graph paper
- Rulers
- Calculators
- Mentor Essential Mathematics pg. 57
- Pencils

- Observation - Oral questions - Written tests

Measurements and Geometry

Reflection - Drawing mirror line given object and image on plane surface
Reflection - Drawing mirror line on Cartesian plane

By the end of the lesson, the learner should be able to:

- Draw the mirror line given an object and its image on a plane surface
- Construct perpendicular bisectors to locate mirror line
- Apply the concept to determining mirror placement in interior design

- Trace objects and their images on plain paper
- Join corresponding points (object to image)
- Construct perpendicular bisector of the line segment
- Verify that perpendicular bisector is the mirror line

How do we find the mirror line given object and image?

- Mentor Essential Mathematics pg. 60
- Plain paper
- Rulers
- Compasses
- Mentor Essential Mathematics pg. 61
- Graph paper

- Observation - Practical work - Written tests

Measurements and Geometry

Reflection - Application in real life situations
Trigonometry - Identifying sides of a right-angled triangle

By the end of the lesson, the learner should be able to:

- Apply reflection in real-life situations
- Solve problems involving reflection
- Use reflection concepts in understanding driving mirrors and road safety

- Discuss uses of reflection in real life
- Solve problems involving town layouts and architectural designs
- Work with peers to apply reflection to practical situations
- Present findings to class

How is reflection used in day-to-day activities?

- Mentor Essential Mathematics pg. 63
- Graph paper
- Rulers
- Digital resources
- Mentor Essential Mathematics pg. 65
- Ladders
- Protractors
- Rulers

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Tangent ratio
Trigonometry - Applications of tangent ratio

By the end of the lesson, the learner should be able to:

- Determine the tangent of acute angles in a right-angled triangle
- Calculate tangent ratios from given measurements
- Apply tangent ratio in calculating heights and distances in surveying

- Measure opposite and adjacent sides in similar triangles
- Calculate ratio of opposite to adjacent for angle θ
- Record ratios and observe that they are constant
- Work out tangent of angles in various triangles

What is the tangent of an angle?

- Mentor Essential Mathematics pg. 67
- Rulers
- Protractors
- Calculators
- Mentor Essential Mathematics pg. 68
- Calculators
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Trigonometry - Sine ratio
Trigonometry - Applications of 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
- Mentor Essential Mathematics pg. 71
- Calculators
- Digital resources

- Observation - Oral questions - Written tests

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
Trigonometry - Solving equations involving 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
- Mentor Essential Mathematics pg. 76
- Exercise books
- Reference books

- Observation - Oral questions - Written tests

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 - 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 - Application in real life situations
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:

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

- Observation - Oral questions - Written assignments

Measurements and Geometry

Area of Polygons - Problems on area of triangle
Area of Polygons - Heron's Formula

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
- Mentor Essential Mathematics pg. 86
- Scientific calculators

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Problems using Heron's Formula
Area of Polygons - Area of a rhombus
Area of Polygons - Area of rhombus given side and angle

By the end of the lesson, the learner should be able to:

- Solve problems on area of triangles using Heron's Formula
- Calculate areas of triangles with all three sides given
- Apply Heron's formula to triangular parks, gardens and stool tops

- Calculate areas of triangular cut-outs
- Work out areas of traditional stool tops
- Solve problems on triangular vegetable gardens
- Present solutions to peers

How is Heron's Formula applied in real life?

- Mentor Essential Mathematics pg. 87
- Calculators
- Exercise books
- Reference books
- Mentor Essential Mathematics pg. 88
- Rulers
- Protractors
- Calculators
- Mentor Essential Mathematics pg. 89
- Protractors

- Observation - Oral questions - Written tests

Measurements and Geometry

Area of Polygons - Area of a parallelogram
Area of Polygons - Area of parallelogram using ab sin θ

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

- Observation - Oral questions - Written assignments

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

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
- Mentor Essential Mathematics pg. 101
- Compasses
- Protractors
- Calculators
- Mentor Essential Mathematics pg. 102
- 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
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:

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

- Observation - Practical work - Written assignments

Measurements and Geometry

Area of a Part of a Circle - Clock and sprinkler problems
Area of a Part of a Circle - Combined 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
- Mentor Essential Mathematics pg. 111
- Exercise books
- Digital resources

- Observation - Oral questions - Written assignments

Measurements and Geometry

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

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

- Observation - Oral questions - Written assignments

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

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
- Mentor Essential Mathematics pg. 117
- 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
Surface Area of Solids - Surface area of frustum of a cone

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

- Observation - Practical work - Written tests

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 - 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
Volume and Capacity - Problems on volume of cones
Volume and Capacity - Volume of cone given slant height

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
- Mentor Essential Mathematics pg. 133
- Calculators
- Exercise books
- Reference books
- Mentor Essential Mathematics pg. 134
- Rulers
- Exercise books

- Observation - Oral questions - Written assignments

Measurements and Geometry

Volume and Capacity - Volume of a pyramid
Volume and Capacity - Problems on volume of pyramids

By the end of the lesson, the learner should be able to:

- Determine volume of square and rectangular-based pyramids
- Apply the formula V = ⅓ × base area × height
- Calculate volumes of poultry houses and storage structures

- Collect objects in shape of pyramids
- Measure vertical height, base length and width
- Calculate volume using V = ⅓ × base area × h
- Compare volumes of different pyramids

How do we find the volume of a pyramid?

- Mentor Essential Mathematics pg. 135
- Pyramid models
- Rulers
- Calculators
- Mentor Essential Mathematics pg. 136
- Calculators
- Exercise books
- Reference books

- Observation - Oral questions - Written tests

Measurements and Geometry

Volume and Capacity - Volume of frustum of a cone
Volume and Capacity - Problems on 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
- Mentor Essential Mathematics pg. 140
- Calculators
- Exercise books
- Digital resources

- Observation - Practical work - Written tests

Measurements and Geometry

Volume and Capacity - Volume of frustum of a pyramid
Volume and Capacity - Problems on 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
- Mentor Essential Mathematics pg. 144
- Calculators
- Exercise books
- Reference books

- Observation - Practical work - 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