Find the perimeter. Simplify your answer.
60'
90-8
4c+6
c-7

6c + (c - 7) + (9c - 8) + (4c + 6) =
= 6c + c - 7 + 9c - 8 + 4c + 6 =
= 6c + c + 9c + 4c - 7 - 8 + 6 = 20c - 9