The perimeter of a rectangle is 30 inches. If its length is three times its width, find the dimensions.

Perimeter = 2*L + 2*W

Let x = width

Length = 3x

2 (3x) + 2 (x) = 30

6x + 2x = 30

8x = 30

x = 30/8 = 3 3/4 inches

So width is 3 3/4 inches and length is 3x so

3 * 3 3/4 = 11 1/4 inches

Length 11 1/4 inches

Width 3 3/4 Inches