A rectangle has length that is 5 more than three times the width. The perimeter of this rectangle is 50. What are the dimensions of the rectangle?

Answer 1

Let L be the length of the rectangle and W be the width. From the first sentence we are told...

L = 3W + 5

Since the perimeter of a rectangle is given by 2L + 2W, the second sentence tells us

2L + 2W = 50

Now we have 2 equations and 2 unknowns. We can solve for W by substituting the 1st equation into the 2nd:

2(3W + 5) + 2W = 50

6W + 10 + 2W = 50

8W = 40

W = 5

Now that we know W, simply plug that into the first equation.

L = 3*5 + 5 = 20