Question

Need help I missed this problem on my test. My answer was 31.8in^2. The right answer was 8.0in^2
How should I have worked the problem:
A pie has a diameter of 9 inches. Each slice of the pie has a central angle of 45 degrees. What is the area of each slice of pie?

Answer 1

A = pi * r^2
A = 3.14 * 4.5^2
A = 3.14 * 20.25
A = 63.585 sq. in.

The pie is divided into 8 pieces.

63.585 / 8 = 7.948 sq. in. >> rounded = 8 square inches.

Answer 2

Find the area of a regular octagon with a perimeter of 80 inches round to the nearest tenth