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

Answer 1

Let L be the length of the rectangle and W be the width of the rectangle. The perimeter is then:

2 * L + 2 * W

Here's what we know:

L = 4 * W

2 * L + 2 * W = 100m

Eliminate one of the unknowns, say L, by substitution:

2 * (4 * W) + 2 * W = 100m

or

8 * W + 2 * W = 100m

W = 10m

Then

L = 4 * 10 = 40 m.

Check:

2 * 10m + 2 * 40m = 100m