Question

An interior angle of a regular convex polygon is 162(degrees). Find the number of sides.

Answer 1

http://www.mathsisfun.com/geometry/polygons.html

Answer 2

So the exterior angle = 180-162 = 18°

sum of exterior angles = 360°
so 18n = 360
n = 20

It is a 20-gon

Answer 3

or, using interior angles,

180(n-2) = 162n
180n-360 = 162n
18n = 360
n = 20