Question

The perimeter of a rectangle is 168 inches. The length of the rectangle is three times its width. Find the dimensions of the rectangle

Answer 1

Given:

The perimeter of a rectangle, P=168 in.

Let w be the width and l be the length of the rectangle.

The length of the rectangle is three times its width.

Therefore,

`l=3w`

Now, the perimeter of the reactnagle can be expressed as,

`P=2(l+w)`

Put l=3w and P=168 in the above equationa and solve for w.

`\begin{gathered} 168=2(3w+w) \\ 168=2*4w \\ 168=8w \\ (168)/(8)=w \\ 21=w \\ w=21\text{ in} \end{gathered}`

Now, the length of the rectangle is,

`\begin{gathered} l=3w \\ =3*21 \\ =63\text{ in} \end{gathered}`

Therefore, the length of the rectangle is 63 in and the width of the rectangle is 21 in.