Area and Circumference

Circle Terms

100

The distance across a circle through its center is called . . .

diameter

200

The distance around the outside of a circle is called . . .

circumference

300

The diameter times 1/2

radius

400

A number that is approximately 22/7 or 3.14

pi

500

The ratio of a circle's circumference to its diameter is called . . .

pi

Radius or Diameter?

100

What is the diameter of a circle with a radius of 31 in?

62 in

200

What is the radius of a circle with a diameter of 108 ft?

54 ft

300

What is the diameter of a circle with a radius of 18.25 mi?

36.5 mi

400

What is the radius of a circle with a diameter of 507.9 km?

253.95 km

500

What is the radius of a circle with a diameter of 16 and 3/5 of an inch?

8 and 3/10 of an inch

Area with Radius

100

Find Area when Radius = 8 ft

200.96 ft²

200

Find Area when Radius = 14 cm

615.44 cm²

300

Find Area when Radius = 0.3 yd

0.2826 yd²

400

Rafay plans to put frosting on a cake that has a radius of 11 inches. How much frosting (in square inches) does he need?

379.94 in²

500

Jeffrey needs to know how much area each of his sprinklers cover when they are spraying water onto his lawn. They spray the water 4.5 feet away and rotate in a circle. Find the area in square feet.

63.585 ft²

Area with Diameter

100

What is the area of a circle with the diameter of 6 m?

28.26 m²

200

What is the area of a circle with a diameter of 14 in?

153.86 in²

300

What is the area of a circle with a diameter of 2.2 yd?

3.7994 yd²

400

Gilly is making a pizza that is 12 inches across. How many square inches of pizza dough does she need (once it is rolled out)?

113.04 in²

500

Sara's bedroom is 15 feet across. She wants to buy a circular rug that will fit her room. What is the biggest size rug she can buy, in square feet?

176.625 ft²

Circumference

100

What is the circumference of a circle with a diameter of 6 in?

18.84 in

200

What is the circumference of a circle with a radius of 31 mm?

194.68 mm

300

What is the circumference of a circle with a diameter of 0.04 ft?

0.1256 ft

400

Jakob wants to put a fence around his circular vegetable garden. If the garden is 30.2 inches across, how much fencing does he need?

94.828 in

500

Marley swims around the edge of a circular pool. If the pool has a radius of 16 feet, how much distance does she cover in one lap?

100.48 ft