Answer:
9. c) 540
10. c) 108
11. e) 1260
12. e) 140
13. b) 2880
14. c) 160
Step-by-step explanation:
The formula to calculate the sum of the interior angles of a polygon is:
(number of sides/angles - 2)*180°
9. a pentagon has 5 sides/angles
(5-2)*180
= 3*180
= 540 (c)
10. Because there are 5 angles, divide the total sum of interior angles by the number of angles.
540/5 = 108 (c)
11. a nonagon has 9 sides/angles
(9-2)*180
= 1260 (e)
12. (same steps as #10)
1260/9 = 140 (e)
13. an 18-gon has 18 sides/angles
(18-2)*180
= 2880 (b)
14. (same steps as #10 and #12)
2880/18 = 160 (c)
Once again, I'm sorry I did not see your notification. Still hope this helped though.