This worksheet is about the perimeter of regular 2D shapes. These are polygons whose sides are all equal in length.

The perimeter is the total distance around the outside of a 2D shape. Calculate the perimeter by adding together all the lengths of the sides.

Example

What is the length of one side?

Perimeter: 70 cm

Answer

First count the number of sides.

There are 10 in this regular shape (decagon).

If the length of 10 equal sides add to 70 cm, we can divide to find the length of one side.

70 ÷ 10 = 7

Each side is 7 cm long.

Remember to put cm in the answer.