Radius, Diameters, Circumference, Area of Circles

A rotating lawn sprinkler sprays water in a circular area of grass, as shown in the picture, The diameter of the circular area of grass is 16 feet. Which measurement is closest to the area in square feet that this sprinkler sprays with water?

• 100.48 ft²

• 50.24 ft²

• 200.96 ft²

• 803.84 ft²

A group of students stood in a circle to play a game. The circle had a diameter of 22 meters. Which measurement is closest to the circumference of the circle in meters?

• 34.54 m

• 1,519.76 m

• 379.94 m

• 69.08 m

A circular railroad-crossing sign has a diameter of 30 inches. Which measurement is closest to the area of the sign in square inches?

• 94.2 in²

• 188.4 in²

• 706.5 in²

• 286.6 in²

• 18.84 square feet

• 28.26 square feet

• 37.68 square feet

• 113.04 square feet

The diagram below shows the radius of the circular opening of a drinking cup. Which of the following is closest to the circumference of the opening in centimeters?

• 12 cm

• 50 cm

• 25 cm

• 8 cm

Daniel wants to buy cookies for her friend. The
radius of a cookie is 5 inches. What is the distance around the cookie?

• 10 in

• 2.5 in

• 15.7 in

• 31.4 in 

The diameter is two times the radius

• True

• False

Does this picture show the diameter or radius of a circle?

• Diameter

• Radius

Does this picture show the diameter or radius of a circle?

• Diameter

• Radius

Determine the radius of the penny

• 59.66 mm

• 9.5 mm

• 38 mm

• 119.32 mm