# Perimeter

The **perimeter** of a 2D shape is *the total length of all its sides*.

For example, a rectangle has four edges, so its perimeter is the total of those four edges added together.

The perimeter of this rectangle is the sum of the length of all its sides:

P = 6 + 6 + 4 + 4 = 20 cm

Some more examples about how to calculate the perimeter of some shapes:

P = 9+8+5 = 22 cm

P = 3+3+3+3 = 12 cm

or P = 4 x 3 =12 cm

P = 6+6+4+3+3 = 22 cm