### Find the measure of each interior angle of a regular polygon of $10$ sides.

$144 ^ \circ$
1. We know that the sum of all exterior angles of a polygon is $360 ^ \circ.$
2. Each exterior angle of a regular polygon of $10$ sides $= { \Bigg ( \dfrac{ 360 } { 10 } \Bigg ) } ^ \circ = 36 ^ \circ.$
3. Thus, each interior angle of a regular polygon of $10$ sides $= 180 ^ \circ - 36 ^ \circ = 144 ^ \circ$.