We're gonna call x the length of the shortest side. The medium side is 3 longer than the shorter side, and the longest side is 14 longer than the shortest (11 + 3 = 14):
Perimeter = shortest side + medium side + longest side 59 = (x) + (x + 3) + (x + 14) 59 = 3x + 17 3x = 42 x = 14
Shortest side = 14 Medium side = 17 Longest side = 28
