Then compare the actual area of the original shape with your first estimate. Practise applying the formula directly to a range of compound shapes based on rectangles.

There are lots of different types of polygon. Find out about quadrilaterals, triangles, polygons and circles in this KS2 Maths guide from BBC Bitesize.

The outside edge of a shape is known as the perimeter. Learn how to work out the perimeter of a 2D shape with this Year 4 article from BBC Bitesize.