Geometry
posted by Anonymous .
The area of a rectangle is 72 square inches and the perimeter is 44 inches. Find its dimensions.

One way to solve this is to find the factors of 72. Then see which of these will fit for the perimeter.

let the length and width be x and y respectively
then
2x + 2y = 44
x + y = 22
y = 22x
area = xy = 72
x(22x) = 72
22x  x^2  72 = 0
x^2  22x + 72 = 0
(x4)(x18) = 0
x = 4 or x = 18
if x = 4, then y = 224 = 18
if x = 18, then y = 2218 = 4
the dimensions are 4 by 18 inches