How_To_Be_Good_At_Math

164 MEASUREMENT •^ PERIMETER

Perimeter

Perimeter means the distance around the edge of a closed

shape. If you imagine the shape is a field surrounded by a

fence, the perimeter is the length of the fence.

To find the perimeter of a shape, we

need to measure the length of each

side and add them all together.

We measure perimeter using the same units

as we use to measure length. It is important

that the sides are in the same unit when we add

them all together.

Look at this tennis court. We can

find the perimeter by adding up

the length of each side:

11 + 24 + 11 + 24 = 70

This means that the perimeter of

the tennis court is 70 m.

TRY IT OUT

Unusual shapes

We measure the perimeter of an

unusual shape in the same way

as a rectangle – just find the sum

of all the sides. Can you add up

the sides of these two shapes to

find their perimeter?

The perimeter of a

shape is the sum of

the lengths of all its

sides.

11 m

24 m

24 m

11 m

20 cm

5 cm

10 cm

12 cm 30 cm

25

cm

20

cm^13

cm

12 cm

15 cm

15 cm

20

cm

Answers on page 319

164_165_Perimeter.indd 164 29/02/2016 18:03