Added by Christopher Fenton on October 10, 2001 at 13:54:24:
P = perimeter
n = number of sides
if polygon is split into triangles so that each triangle is isoseles extending from the center and finishing at the perimeter... (diagram below)
...Area = n((p/2n(p/2n * tan((180-(360/n))/2)))
where p/2n = 1/2 base of a triangle
p/2n * tan((180-(360/n))/2)) = height of triangle
and the triangles are like this
----------- square as an example
-- -- triangles formed from the center
- - - - point (c) towards the ends of the
- - - - sides (the vertices)
- - - -
- c -
- - - -
- - - -
- - - -
-----------