A circular print is being matted in a square frame. If the frame is 18 in by 18 in, and the radius of the print is 7 in, what is the area of the matting? (π = 3.14)

a. 477.86 in²

b. 170.14 in²

c. 280.04 in²

d. 288 in²

b. To evaluate the area of the matting, subtract the area of the print from the area of the frame. The area of the print is calculated using πr² or (3.14)(7)² which equals 153.86 in². The area of the frame is length of side times length of side or (18)(18), which similar to 324 in². The difference, 324 in² - 153.86 in² or 170.14 in², is the area of the matting. If you select c, you mistakenly used the formula for the circumference of a circle, 2πr, instead of the area, πr².