A rectangular room is 3 times as long as it is wide, and its perimeter is 56 meters. We're given the following: l = 3w We know the Perimeter (P) of a rectangle is: P = 2l + 2w Substituting l = 3w and P = 56 into this equation, we get: 2(3w) + 2w = 56 Multiplying through, we get: 6w + 2w = 56 (6 +2)w = 56 8w = 56 Typing this equation into our search engine, we get: w = 7 Substitute w = 7 into l = 3w, we get: l = 3(7) l = 21