Question

The area of a square rug is 144ft squared. There is a 3-ft wide space between each edge of the rug and the wall. What is the area of the floor not covered by the rug?

Answer 1

It helps to draw a picture so you can visualize it better.  

For the rug, since the area = 144, what two numbers multiplied give you 144? You might already know that 144 is a perfect square, so 12 x 12 = 144. 12 is the length of each side of the rug.  

√144 = 12  

12 + 3 = 15. (Add 3 because the rug only covers a portion of the floor. The entire floor = the length of the rug + the part that isn't covered)  

15 x 15 = 225 ft squared (Multiply both sides of the floor to get the area.)  

225 ft squared - 144 ft squared = 81 ft squared <-- your answer