Matt invests $2,070 in a savings account with a fixed annual interest rate of 6%
compounded 12 times per year. What will
the account balance be after 11 years?

When solving for x, we know that the sum of a polygon's interior angles will always comply with the formula. The formula to solve for the sum of the interior angles is: (n - 2)(180). 

For this specific problem, all we need to do is plug in 6 for n. The new equation will be (4)(180).

4*180 = 720. Therefore, the sum of the interior angles would be 720 degrees, however, we can't stop there since we're solving for x.
 
The next step is to add up all of the other angles.

160 + 75 + 132 + 113 + 108 + x = 720.

x + 588 = 720

*Subtract 588 from both sides* 

x = 132