9. -7/12
10. -2.75
11. 1.844
12. 4.539
Because the nonagon is regular, the angles are equal. Nona means nine. The total of the measures of the interior angles of any polygon is (n-2)180. Use this formula to find the measure of one interior angle.
(9-2)180
7*180=1260. Divide by 9 to get the measure of one angle.
1260/9=140
The answer is 140 :)
Answer:
54
Step-by-step explanation: