Finding the perimeter of a rectilinear shape

Home learning focus

Learn how to find the perimeter of a rectilinear shape.

This lesson includes:

  • one video
  • three interactive activities

Learn

What is the perimeter?

This shape looks much more complicated than a rectangle, but the method of working out the perimeter is exactly the same.

Add together the lengths of all the sides to find it.

2 + 2 + 3 + 3 + 5 + 5 = 20

The perimeter is 20 cm

Finding the unknown sides

Watch the video below from BBC Bitesize on finding the perimeter of a rectilinear shape when you don't know the length of every side.

A rectilinear shape is a shape that has straight sides and right angles.

Practise

Activity 1

Perimeter worksheet

Try this worksheet from Classroom Secrets Kids. Print it out or write your answers on paper.

Perimeter worksheet

Finished? Check your answers here.

Activity 2

Make a shape

Cut out 12 squares of paper of equal size or use 12 square sticky notes (you may have these from yesterday's activity). Arrange them into a rectilinear shape.

What is the perimeter of this shape?

Now rearrange the pieces of paper into a new shape. How many different shapes can you make and find the perimeter of?

Activity 3

Rectilinear shapes

Try the worksheet below from Pearson Power Maths.Print it out or write the answers on paper.

Rectilinear shapes

All done? Check the answers here

There's more to learn

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

KS2 Maths
Bitesize Daily lessons
Primary games
7 - 11 Maths
Take on the Maths Challenge!
Malory Towers