Answer:
c. a: 4
b: 12
c: 9
4x² +12x+9=0
(2x+3)(2x+3)= 0
(2x+3)²=0 {square root both sides}
2x+3=0
2x=-3
x= -3/2
The sum of the interior angles of a polygon is (n-2)*180, n being the number of sides.
a nonagon has nine sides, so the total of interior angles is (9-2)*180=7*180
this is a regular nonagon, so each interior angle has the same degrees:
7*180/9=7*20=140
the exterior angle=180-the interior angle=180-140=40
40 is the correct answer.
Answer:
180
Step-by-step explanation:

192-12=180
The answer is b so good luck and i hope that helps