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How do you calculate perimeter?

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.

### How do you calculate the perimeter of an object?

### Need more practice?

Complete
this perimeter activity sheet (Word 294 kb)