You can put this solution on YOUR website! Each angle of a regular n-gon measures 156 degrees. How many sides does the n-gon have?
----
Each corresponding exterior angle is 180-156 = 24 degrees.
----
Fact: The sum of the exterior angle is 360
----
The number of exterior angles is 360/24 = 15
-----
Therefore the number of sides must be 15
=======================
Cheers,
Stan H.