The length of a rectangle is four times its width. If the perimeter of the rectangle is 100 in, find its length and width.

Length: 40 inches

Width: 10 inches

Step-by-step explanation:

Let width of the rectangle.

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

Length =

- - - -

Perimeter = (formula for perimeter of rectangle)

(combine like terms)

inches

∴ The width of the rectangle is 10 inches.

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

Length =

inches

∴ The length of the rectangle is 40 inches.

Hope this helps :)