# Area of a Circle Practice Problems with Answers

There are twelve (12) practice problems in this exercise about the area of the circle. You may use a calculator. Do not round intermediate calculations.

For your convenience, I have included the different variations of formulas that you can use to find the area of a circle.

Problem 1: What is the area of a circle with radius 8 meters? Leave your answer in terms of \large{\pi}.

This problem requires us to leave our answer in terms of \pi.

\color{red}64\pi square meters

Problem 2: The diameter of a circle is 4.5 feet. Find its area. Use \pi = 3.1416.

\color{red}15.90 square feet

Problem 3: Find the area of the circle below with a given radius. Use \pi = 3.14

\color{red}907.46 square centimeters

Problem 4: Find the area of the circle below with a given diameter. Use the value of \pi on your calculator.

Make sure that you use the internal value of \pi on your calculator.

\color{red}60.00 square inches

Problem 5: The circumference of a circle is 22.2 feet. What is its area? Use \pi = 3.14

\color{red}39.24 square feet

Problem 6: Determine the area of a dinner plate with a circumference of 37.68 inches. Use \pi = 3.14.

\color{red}113.04 square inches

Problem 7: The radius of a circle is 5 inches. Find the area of the circle expressed in square centimeters c{m^2}. Use 1 in = 2.54 cm. Use \pi = 3.14.

Convert 5 inches to centimeters.

The area is

\color{red}506.45 square centimeters

Problem 8: The diameter of a circle is 12.4 miles. Calculate the area of the circle in terms of square kilometers k{m^2}. Use 1 mi = 1.609 km. Use \pi = 3.1416.

Convert 12.4 miles to kilometers.

The area is

\color{red}312.64 square kilometers

Problem 9: What is the radius of a circle with an area of 73.12 square miles m{i^2}? Use \large{\pi = {{22} \over 7}}.

\color{red}4.82 miles

Problem 10: Determine the diameter of the circle having an area of 100 square yards y{d^2}. Use \large{\pi = {{22} \over 7}}.

\color{red}11.28 miles

Problem 11: Find the area of the semicircle below with a diameter of 8 centimeters. Use \pi = 3.1416.

The area of a semicircle is half of the area of a circle.

\color{red}27.33 square centimeters

Problem 12: Both circles share the same center. Find the exact area of the shaded region.