Area of a rectangle is 2(Length) plus 2(Width) so the side unknown is x suppose you know the width do not know the length and know the perimeter then you have the equation Suppose the width is 5 and the perimeter is 22 5(2)+x(2)=22 10+2x=22 2x=22 x=11 Hope that helped!
SOLVE = to find the side length of a retangle you must multiply the width by 2 then you need to need to subtract the perimeter from the answer you got above
