Answer:
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°
