How do you work out the area of a triangle?

Area of a triangle

To calculate the area of a triangle, multiply the height by the width (this is also known as the 'base') then divide by 2.

Find the area of a triangle where height = 5 cm and width = 8 cm.

5 × 8 = 40 ÷ 2 = 20

The area is 20cm².

A triangle is always half the area of a rectangle with the same height and width.
Play Bitesize games

There's more to learn...

This guide
A red triangle and a blue rectangle.

How do you work out the area of triangles?