Answer :
We suppose we have a regular polygon with n sides, then the measure of each one of the interior angles is given by:
[tex]\frac{180(n-2)}{n}[/tex]For example, if we want to know the measure of a regular pentagon (which has 5 sides), we replace the value of n by 5,
[tex]\frac{180(5-2)}{5}=\frac{180(3)}{5}=\frac{540}{5}=108[/tex]And we obtain that each one of the interior angles of the pentagon is 108°.