12. Find the sum of the interior angles of a polygon with 19 number of sides
a. 3060°
b. 3070
c. 3080°
d. 3090°

13.What is the number of sides of a polygon with 3240 sum of its interior angles?
a.16
b.17
c.18
d.19

14.Determine the number of sides of regular polygon with 20 measure of external angle.
a.17
b.18
c.19
d.20