Sum of the interior angles of a convex polygon

Author:
Mathguru
Topic:
Angles
On the screen, we can see a regular polygon and we can change the number of its side by using the slide bar. Interior angle is mentioned, as this is a regular polygon all interior angles will remain equal. Let us change the value of n and move points A & B and observe how the shape and size gets changed.
What relation do you observe between the sum of interior angles and value of n?