Problem:
For how many values of will an -sided regular polygon have interior angles with integral degree measures?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Since the degree measure of an interior angle of a regular -sided polygon is , it follows that must be a divisor of . Since , its divisors are of the form with or , or and or . Hence, there are divisors of . Since , we exclude the divisors and , so there are possible values of .