The rectangle in the following figure has a base that equals three times its height. Find an expression for the rectangle's perimeter (P) as a function of its base.

Ok. Length = L, Base = B
P = 2L + 2B
We know that B = 3L or L = B/3
so that's P = 2/3B + 2B = 2/3B + 6/3B = 8/3B