Find the measures of an interior angle and exterior angle of a regular 18-gon

interior angle : 160°

exterior angle : 20°

Step-by-step explanation:

formular of interior angles of regular polygons:

((number of apexes-2) * 180°) / (number of apexes)

examples:

triangle : (3-1) * 180°/3=180°

square : (4-2) * 180°/4=90°

back to our question:

interior angle : (18-2) * 180°/18=160°

exterior angle = 180° - interior angle = 180°-160°=20°