Question 562200
a) Quadrilateral can be divided into two triangles (each with vertices at the vertices of the quadrilateral) so the sum of the angles is 2*180 = 360


b) Same logic as a) but now we can divide into three triangles --> 3*180 = 540


c) 4*180 = 720


We can generalize to n sides and derive the sum of the angles of an n-gon to be 180(n-2).