To solve for C, you have to get both of the numbers with a C on the same side. So, subtract the 5c from the right side onto the left side.

Then, divide by 3 on each side.

So, c = 7.
I am pretty sure the answer is 2,520.
Answer:
D. <B = 141°
Step-by-step explanation:
The <u>sum of interior angles</u> of a polygon is
(n-2)*180, where n is the number of sides!
Sum of angles for our polygon that has 7 sides must be:
(7-2) *180 = 5*180 = 900
Sum of angles that are in the picture are:
120+129+130+142+90+148+ <B = 759 + <B
<B = 900 -759 = 141°
Check our work:
120°+129°+130°+142°+90°+148°+ 141° = 900°✅
The two opposite arcs add to the entire circle, 360 degrees, so we must have EFG=360-60=300 degrees.
Answer: C