14. Rachel added the lengths of three sides of a rectangle and got $44 \mathrm{~cm}$. Heather added the lengths of three sides of the same rectangle and got $40 \mathrm{~cm}$. What is the perimeter of the rectangle?
A $42 \mathrm{~cm}$
B $56 \mathrm{~cm}$
C $64 \mathrm{~cm}$
D $84 \mathrm{~cm}$
E $112 \mathrm{~cm}$
14. B Let the length of the rectangle be $x \mathrm{~cm}$ and let the width be $y \mathrm{~cm}$. The information in the question tells us that $2 x+y=44$ and $x+2 y=40$. Add these two equations to obtain $3 x+3 y=84$. Hence $x+y=28$ and so the perimeter, which is equal to $2(x+y) \mathrm{cm}$, is $56 \mathrm{~cm}$.