if a simple figure has n sidesto find the sum sof the angles

if a simple figure has n sides,to find the sum (s)of the angles of that figure you use the formula:
s=180(n-2)

Solution

a triangle has 3 sides...angles=180
any 4-sided figure can be split into 2 triangles...so 2 triangles = 2*180
any 5-sided figure can be split into 3 triangles...so 3 triangles = 3*180
blah blah blah...
any 24-sided figure can be split into 22 triangles...so 22 triangles = 22*180 etc. See? Now this explains the formula, doesn\'t it?
eg what is the sun of the interior angles of a 16 sided figure?
Answer... well, a 16-sided figure can be split into 14 triangles, so 14*180 = whatever