Hello from MrBillDoesMath!
Answer:
a = 36
b = 12
c = 11
Discussion:
Converting the problem into mathematical symbols:
a = 3b (I)
c = b - 1 (II)
a + b + c = 59 (III) (the perimeter is 59, we were given that)
Substitute (I) and (II) into (III)
a + b + c = 59
3b + b + (b-1) = 59 =>
5b -1 = 59 =>
5b = 59 + 1 = 60 =>
b = 60/5 = 12.
As a = 3b, a = 3 (12) = 36, and c = b-1 = 12-1 = 11
Thank you,
MrB