Question

GEOMETRY: The formula for the perimeter of a rectangle is P=21 + 2w, where l is the length and w is the width. A rectangle has a perimeter of 24 inches. Find its

dimensions if its length is 3 inches greater than its width.

a. 6 in. by 9 in.
b. 4 in. by 7 in.
c. 5 in. by 7 in.
d. 4.5in. by 7.5 in.

Answer 1

d) 4.5in * 7.5 in

Explanation:

24 = 2L + 2W

L = W+ 3

then:

24 = 2(W+3) + 2W

24 = (2*W + 2*3) + 2W

24 = 2W + 6 + 2W

24 = 4W + 6

24 - 6 = 4W

18 = 4W

W = 18/4

W = 4.5

L = W+3

L = 4.5 + 3

L = 7.5

Check:

24 = 2(L+W)

25 = 2(7.5 + 4.5)

24 = 2*12