For #9 - 14, for each of the regular polygons, find the sum of the measures of the inte and then find the measure of each interior angle.
Pentagon:
9. Sum = a) 360
b) 480 C) 540
d) 620 e) 700
10. Each = a) 72
b) 96
c) 108
d) 124 e) 140
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Nonagon:
11. Sum = a) 1035 b) 1090 1165
12. Each = a) 115 b) 121
d) 1225 e) 1260
d) 136
e) 140
c) 130
-
18-gon
13. Sum = a) 2720 b) 2880 C) 3040 d) 3200 e) 3360
14. Each = a) 120 b) 140
c) 160 d) 180 e) 200

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.