### AREA AND PERIMETER OF PLANE SHAPES LESSON NOTE AND LESSON PLAN FOR PRIMARY, SECONDARY AND HIGH INSTITUTIONS

W.A.L.A: AREA AND PERIMETER OF PLANE SHAPES

Monday
Area  of rectangles and squares
Resources

Content
The area of any given shape is the measure of the extent of a surface. Area is measured in square units.
The perimeter of any given shape is the sum of the distance of all the lengths of the sides of that shape.

Examples:
Find the area of a rectangle whose length is 6cm and width 4cm.

A rectangle is 10m long and 7m wide. What is the area?
Solution
Area = L X B
= 6cm X 4cm
= 24 cm²
Area = L X B
= 10 m X 7 m
= 70 m²

Area of Square
Area of square = L²  or S². where L= length and S = sides

Examples: Calculate the area of these squares with the following sides.
7 cm
9 m
Solution
Area = L²
= 7cm X 7cm
= 49cm²
Area = S²
= 9m  X 9m
= 81m²

Pupils should be Able to ;
Find the area rectangles and squares

Begin the lesson by asking the pupils to measure the length and breadth of the squares and rectangles

Tuesday
Area of triangle

The formula for finding area of triangle is 1/2 b x h. Where b is base and h is height of the triangle.

Examples : find the area of the following triangles.

Find the area of a triangle with base of 12m and height of 9 m.
Solution
Area = 1/2 bh
=   1/2 X b X h
=   1/2 X 8cm X 6 cm
= 24cm²

Area of Circle
Area = 1/2  bh
=   X b X h
=   X 12cm X 9 cm
= 54cm 2

Pupils should be Able to
Find the area of triangle

Begin the lesson by asking them to;
identify a triangle
Then tell them to measure the shapes in centimetres and meters.

Wednesday
Perimeter of squares and rectangles

Examples : find the perimeter of these shapes.
A rectangle with length of 8cm and breadth of 5cm.
A square of sides 9m each.
Solution
Perimeter= L+ B + L + B
= 8cm + 5cm + 8cm + 5cm
=26cm
OR Perimeter =  2 ( L+ B )
= 2 ( 8cm + 5cm)
= 2 X 13cm
= 26cm
Perimeter of square  = L + L + L + L
=  9m + 9m + 9m +9m
= 36m
OR       Perimeter of square= 4 L
= 4 X 9m
= 36m

Pupils should be Able to ;
State the formulae for finding perimeter of rectangle and square
Begin the lesson by measuring the length of the shapes to be used.

Thursday
Perimeter of triangles

EXAMPLES: find the perimeter of the following shapes with sides :6cm            9cm             5m

and        8cm             4m          7m
Solution
Perimeter = 6cm + 9cm + 8cm
= 23cm

Perimeter =  5m + 4m + 7m + 6 m
=22m

Pupils should be Able to ; calculate the perimeter of any given shapes

Begin the lesson by measuring the sides of the various shapes given.