Question

A rectangle has a length that is 3 times its width. If the perimeter of the rectangle is 20 in, what is the area?

Answer 1

Given

length = 3 times width

Let w = width, and l = 3w

Then the perimeter is

2l + 2w = 20 in

2(3w) + 2w = 20 in

6w + 2w = 20 in

8w = 20 in

w = 2.5 in

l = 3w

l = 3(2.5 in)

l = 7.5 in

Now that we have length and the width, we can now solve for area.

`\begin{gathered} A=lw \\ A=(7.5\text{ in})(2.5\text{ in}) \\ A=18.75\text{ in}^2 \end{gathered}`

Therefore, the area of the rectangle 18.75 square inches.