Question

The length of a rectangle is four times its width.

If the perimeter of the rectangle is 100 in, find its length and width.

Answer 1

Length: 40 inches

Width: 10 inches

Explanation:

Let
`x =` width of the rectangle.

From the information "length of a rectangle is four times its width", we can express the length as:

Length =
`4x`

- - - -

Perimeter =
`2l+2w` (formula for perimeter of rectangle)

`100=2(4x)+2(x)`

`100=8x+2x`

`10x=100` (combine like terms)

`x=10` inches

∴ The width of the rectangle is 10 inches.

To find the length of the rectangle, we can use substitution:

Length =
`4x`

`=4(10)`

`=40` inches

∴ The length of the rectangle is 40 inches.

Hope this helps :)