Measure and calculate perimeter

Home learning focus

Learn how to measure and calculate the perimeter of shapes in centimetres and metres.

This lesson includes:

  • two videos
  • two interactive activities
  • one worksheet


This video will help you to understand how to measure the perimeter of a shape. Why not make some notes as you watch the video to help you to remember later?

Calculating perimeter

The perimeter is the distance all the way around the outside of a 2D shape.

To work out the perimeter, add up the lengths of all the sides.

The perimeter of the shape shown is 10 + 10 + 6 + 6 = 32

As the crow flies

Watch up to 01:58 of this video from BBC Teach. It shows you how to calculate the perimeter of regular and irregular polygons. Polygons are shapes with many sides.

It also gives you a handy method to work out the missing lengths of sides. Don't forget to record the units of measurement!


Activity 1

Work out the perimeter of the park

Add together all the sides to work out the perimeter of the park.

Activity 2

Work out the missing lengths

Use what you have learnt to work out the perimeter of the next park. Can you work out the lengths of the sides that are not marked?

Activity 3

Calculate perimeter

Print out and complete the activity below from Twinkl to work out the perimeter of some regular and irregular polygons.

Calculate perimeter

The answers can be found here.

There's more to learn

Have a look at these other resources around the BBC and the web.

Bitesize Daily lessons
KS2 Maths
7 - 11 Maths