Pat is making a Christmas tree skirt. She needs to know how much fabric to buy. Using the example provided, calculate the area of the skirt to the nearest foot.

a. 37.7 ft²

b. 27 ft²

c. 75 ft²

d. 38 ft²

d. To determine the area of the skirt, evaluate the area of the outer circle minus the area of the inner circle. The area of the outer circle is π (3.5)² or 38.465 in². The area of the inner circle is π (.5)² or .785 in². The difference is 38.465 - .785 or 37.68 ft². The answer, rounded to the nearest foot, is 38 ft². If you select a, you rounded to the nearest tenth of a foot. If you select b, you calculated the radius of the outer circle as being 3 feet instead of 3.5 feet.