Question

Find the measures of each interior angles of a regular polygon having $15$ sides

Answer 1

In a regular polygon, all sides are of same size and measure of all interior angles are the same.
The sum of interior angles of polygon of $15$ sides is :
$(n-2)\times {180}^o$ where $n$ is the number of sides of polygon

$(15-2)\times {180}^o={1440}^o$ here $n=15$

Each interior angle $=2340/15={156}^o$