The perimeter is the distance around the boundary or outside of a closed geometrical object. For instance, in order to make a flange around a rectangular duct, you will need to calculate the perimeter of the duct first. This will help you work out the amount of material you require.
The perimeter (P) of a rectangle is P = 2(l + b), where l = length and b = breadth
The perimeter (P) of a square is P = 4s, where s = length of the sides.
The perimeter (P) of a triangle is P = a + b + c, where a = length of one side, b = length of another side, c = length of the third side.
Complete this perimeter activity sheet (Word 294 kb)