Practice!

Sample Problem

Superman uses 16 meters of fencing to create a rectangular field. If one side is already built, and the width is known to be 4 meters, what is the area encompassed by the rectangular fence?

  m2

Solution

Since we don’t need one side of the width, Superman doesn’t need fencing for that side. He needs to build two lengths and one width, which we know is 4 meters long. Thus, the length of the rectangular fence is (16 - 4) ÷ 2 = 6 m. The area of the field is therefore 6 × 4 = 24 m2.