EXAMPLE 2.6.2

The diagram below shows the plan for a new parking lot at the Southwestdale Mall. It is estimated that such construction costs $12 per square yard. What will be the total cost for the parking lot?

 

SOLUTION

We need to find the area (in square yards) of the parallelogram-shaped region, and multiply by the cost factor of $12 per square yard.

The formula for the area of a parallelogram is Area = base times height

In the given parallelogram, b = 960 feet and h = 540 feet. However, since we want to compute area in square yards, not square feet, we should convert these measurements from feet to yards before using the formula for area. To convert from feet to yards we divide by 3.

base = 960 feet = 320 yards
height = 540 feet = 180 yards

Now we compute the area:

Area = (320 yards)(180 yards) = 57,600 square yards

Finally we find the total cost:

Cost = (57,600square yards) times ($12 per square yard) = $691,200

The correct choice is B.