The johnson's living room rug is 3 sq units wide and 4 sq units long. what is the area of the rug?

Well, the easiest way to do this is simply by using the formula. The area of a rectangle is given by the formula 
AREA= LENGTHXWIDTH
    The reason why i'm using the formula for the area of a rectangle is because a room is usually the shape of a rectangle. Anyway;
The length is 4
The width is 3
  So that is basically
AREA=4 x 3
AREA= 12. 
  So the area is 12n² 
  Hope i helped. Have a nice day

The answer would be b