Answer:
1) 162
2)
1) b) 120
2) e) 90
3) a) 72
4) c) 60
3) 49
Explanation:
1) n = 20
each interior angle is given by:

2)
Measure of one exterior angle of a polygon with n sides is :

(1) triangle : 3 sides
exterior = 360/3 = 120
(2) quad : 4 sides
exterior = 360/4 = 90
(3) pentagon : 5 sides
exterior = 360/5 = 72
(4) hexagon : 6 sides
exterior = 360/6 = 60
3) The shape isa quadrilateral (n = 4)
Sum of interior angles is:
(n-2)* 180
= (4 - 2)*180
= 2*180
= 360
⇒ (2x + 15) + (3x - 20) + (x + 15) + (x + 7) = 360
⇒ 7x + 17 = 360
⇒ 7x = 360 - 17
⇒ 7x = 343
⇒ x =

⇒ x = 49