Answer :
Remember that
The sum of the interior angles in any polygon is given by the formula
[tex]S=180^o(n-2)[/tex]where
n is the number of sides of the polygon
In this problem
n=15
substitute
[tex]\begin{gathered} S=180^o(15-2) \\ S=2,340^o \end{gathered}[/tex]Divide by the number of sides to obtain the measure of each interior angle
[tex]\frac{S}{n}=\frac{2,340}{15}^o=156^o[/tex]