11.3 Calculation of Perimeter

1. Perimeter of regular shape

The perimeter is the length of the outline of a shape. To find the the perimeter of a rectangle or square you have to add the lengths of all the four sides.

• For example, if a circle is made of a metal wire of length L, then the same wire we can use to construct a square, whose sides are equal in length.

2. Perimeter of Irregular shapes

Irregular shapes have sides and angles of any length and size.

1. Calculating the perimeter using a grid sheet or grid box