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?

A. $2,073,600

B. $691,200

C. $6,220,800

D. $518,400

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 area of a parallelogram is expressed in the following illustration:

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.

Now we compute the area:

Area = (320 yd.)(180 yd.) = 57,600 sq. yd.

Finally we find the total cost:

Cost = (57,600 sq. yd)($12 per sq. yd.) = $691,200

The correct choice is B.