Question 136671
If you take one side of a regular polygon and the two segments that connect the endpoints of the side to the center, you will have formed a triangle.  The length of the side of the polygon is the base of the triangle and the distance from the side to the center is the altitude or height of the triangle.  Since there is one of these triangles for every side of the polygon, the total area of the polygon is the number of sides times the area of the triangle.  The area of one triangle is {{{A[T]=(1/2)bh}}} where b is the length of the base and h is the height.  The area of the entire polygon is then {{{A[P]=(1/2)nbh}}} where n is the number of sides.