Question

The length of a rectangle is 4 in longer than its width.

If the perimeter of the rectangle is 28 in, find its area.

Answer 1

45in²

Explanation:

P = 28

l = w + 4

Use the equation for perimeter:

P = 2l + 2w

P = 2(w+4) + 2w

P = 2w + 8 + 2w

P = 4w + 8

Since we know P=28, we can solve for w.

P = 4w + 8

28 = 4w + 8

4w = 20

w = 5

Substitute w=5 into the length formula

l = w + 4

l = 5 + 4

l = 9

With l=9 and w=5, find the area using the area formula for rectangle.

A = lw

A = (9)(5)

A = 45

The area of the rectangle is 45 squared inches.