1. What Is Area ? Area is the amount of space inside a shape: Area Area
1cm
Area is measured in square centimetres.
1cm2
A square centimeter is a square measuring one centimeter in each direction.
It is written as :

2. Estimating The Area B A C D
Look at the four shapes below and use your judgement to order them from smallest to largest area: A B C D

3. B A C D To decide the order of areas consider the four shapes again:
To measure the area we must determine how many square centimeters are in each shape:
Each shape is covered by 36 squares measuring a centimeter by a centimeter. We can now see that all the areas are equal at 36 cm2 each.

4. Area Of A Rectangle.
Look again at one of the shapes whose area we estimated: C
Length
Width
What was the length of the rectangle ?
9cm
How many rows of 9 squares can the width hold ? 4
We can now see that the area of the rectangle is given by 9 x 4.
The formula for the area of a rectangle is:
A = LW
for short.
Area = Length x Width or

5. We can now calculate the area of each rectangle very quickly:
(1)
(2)
A= L x W
A = 12 x 3 =36 cm2
(3)
A= L x W
A = 6 x 6 =36 cm2
A= L x W
A= L x W
(4)
A = 18 x 2 =36 cm2
A = 9 x 4 =36 cm2

6. Example 1
Calculate the area of the rectangle below:
(2) 3m 5m
7cm
4cm
(1)
Solution
This area is in square meters: 1m
A = LW
Solution
A = LW
L = 7
W = 4
L = 3
W = 5
A = 7 x 4
A = 3 x 5
A = 28 cm2
A = 15 m2

7. Example 3.
Solution.
8cm
2cm
5cm
3cm
Split the shape up into two rectangles: A1
Calculate the area of A1 and A2. A2 2 A1 A2 3 5 6
Calculate the area of the shape above:
Area = A1 + A2
Area = ( 2 x 5) + (6 x 3)
Area =
Area = 28cm2

8. What Goes In The Box ? Find the area of the shapes below : (1) 8cm 6cm
(2)
48cm2
(3)
17cm
8cm
12cm
5cm
11.34m2
141cm2