Answer:
Cost: 1116 dollars to carpet the lobby........
* Note (this is if the lobby costs a dollar per square foot, if not, simply multiply 1116 square feet by the actual cost per square foot to get the cost to carpet the lobby)
Explanation:
Here I'm assuming that a square foot will cost a dollar respectively. So, let's start with the the area of the figure. We see that the figure is composed of two trapezoids of equivalent area, so lets calculate the area of one of them-
The formula of a trapezoid is: (Base1 + Base2 / 2) * height
Here the first base represents 30 feet, the second base 42 feet, and the height 15.5 feet. Substitute:
( 30 + 42 / 2 ) * 15.5 =
( 72 / 2 ) * 15.5 =
36 * 15.5 =
Area of one trapezoid: 558 square feet
Multiply this area by two to receive the area of the whole figure:
558 * 2 =
Area of the figure: 1116 square feet
So, assuming that a square foot will cost a dollar, it will cost 1116 dollars to carpet the lobby