A worker at a framing store is making a rectangular frame. He knows that the perimeter
of the frame is 144 in. and the length is 40 in. How can he determine the width of the
frame?
The length of one side of the rectangle is 40, so multiply it by 2 to get 80. Subtract it off the total of the perimeter, 144 - 80 = 64. Then, divide it by 2 to get the width, 64/2 = 32.