Perimeter
From Wikipedia, the free encyclopedia.

The perimeter is the distance around a given two-dimensional object. For a polygon it is calculated by adding the lengths of all of the sides.

For circles the equation is P= 2 &pi r, where r is the radius and &pi is the mathematical constant.

See also:

• isoperimetric theorem

The original article can be found at: http://en.wikipedia.org/wiki/Perimeter.
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