Question

What's the formula of a 28 sided polygon??

Answer 1

(N = # of sides and S = length from center to a corner)

Area of a regular polygon = (1/2) N sin(360°/N) S2

Sum of the interior angles of a polygon = (N - 2) x 180°

The number of diagonals in a polygon = 1/2 N(N-3)

The number of triangles (when you draw all the diagonals from one vertex) in a polygon = (N - 2)