Perimeter of square and rectangle

In this exercise you compute the perimeter of a square or a rectangle. The perimeter is the sum of the lengths of all sides around the figure. A square has four equal sides, so you simply multiply one side by four. A rectangle has two pairs of equal sides – the longer one (a) and the shorter one (b).

What does the generator do?

The generator picks a square or rectangle at random, along with a unit (cm, m, or mm). The sides are whole numbers between 2 and 20, so the perimeter is always a whole number that can easily be worked out in your head.

How to use it

Look at the figure and notice the side lengths. If it is a square, multiply the side by four. If it is a rectangle, add the longer and shorter side and multiply the result by two. Type the number into the box next to “P =” and press “Check”.