What will be the cost

Question

Crown molding is to be installed in a 13-foot-wide by 30-foot-long living room. The subcontractor charges $3per foot to install the molding. What will be the cost for the room

Answer 1

As described, the room is a rectangle.  The molding will go around the edge of the ceiling, around the PERIMETER of the room.  So the amount of molding will be equal to the perimeter. 

 

The formula for the perimeter of a rectangle is 2(L + W), where L is the length and W is the width.

 

In this case, that means 2(13 + 30) = 2(43) = 86 feet.

 

At $3 per foot, the cost will be 3*86, or $258