Finding the
Area of a
Rectangle
Area of a Rectangle
Objectives
• To calculate areas of rectangles
• To calculate areas of polygons
made of rectangles
Area of a Rectangle
Area is the measure of how much space a
shape takes up. We measure it in squares such
as square centimetres or metres etc.
1 cm
1 cm
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
This rectangle takes
up 28 squares.
It has an area of 28
square centimetres
28 cm2
Area of a Rectangle
It could take a long time to cover shapes in
squares. Luckily there is an quicker way.
7 cm
4 cm
×
= 28 cm2
Area of a Rectangle
Use this formulae to find the area of
rectangles.
length
breadth
Area of a rectangle = length × breadth
Area of a Rectangle
Can you find the areas of these rectangles?
5 cm
15 cm2
2 cm
3 cm
14 cm2
7 cm
7m
49 m2
7m
Area of a Rectangle
Can you think of a way to find the
area of this shape?
5 cm
6 cm
7 cm
3 cm
12 cm
Area of a Rectangle
Split the shape into rectangles?
5 cm
6 cm
7 cm
3 cm
12 cm
Area of a Rectangle
Find the area of each rectangle?
5 cm
5 × 6 = 30 cm2
7 × 3 = 21 cm2
6 cm
7 cm
3 cm
Area of a Rectangle
Add the areas together to find the area of the
complete shape?
30 + 21 = 51 cm2
30 cm2
21 cm2
Area of a Rectangle
Can you find the areas of these shapes?
2 cm
6m
4 cm
22 m2
3m
4m
11 cm
43 cm2
7 cm
1m
4m
5 cm
Area of a Rectangle
Here is a challenge can you work out the area
of this shape with a hole in it?
2 cm
5 cm
5 cm
10 cm
Clue: Take the area of the hole from the area of the whole!
50 cm2 – 10 cm2 = 40 cm2
Remember:
Area of a rectangle = length × breadth
length
breadth
Split more complicated shapes into
rectangles and find the area of each
rectangle then add them together.
Over to you.