There are 4 sides to a rectangle, which we will name as x as we do not know their length yet. We will be adding up these 4 sides as we are given the perimeter. However, we know that the length of the of the rectangle is 8 units longer than its width, which will make them x+8 units long. So, our equation is: x+(x+8)+x+(x+8)=56 where x is a measure of the width and (x+8) is a measure of the length. Now we solve, first collecting the like terms: x+x+8+x+x+8=56 4x+16=56 Now minus 16 on both sides: 4x=40 And finally divide by 4 on both sides to isolate x: x=10 So, the width (x) is 10 units, and the length (x+8) is 12 units.