Quandaries
and Queries 

Name: ashish Who is asking: Other Question: 

Hi Ashish, Suppose that the pentagon is concave. Choose one of the vertices and draw the diagonals from the two opposite vertices to subdivide the pentagon into three triangles.
The sum of the interior angles of the pentagon is the sum of the interior angles of the three triangles. The sum of the interior angles of a triangle is 180^{o} so the sum of the interior angles of the pentagon is 3 times 180^{o} which is 540^{o}. What if the pentagon is not convex?
Penny 

