Circles Review

Parts of a Circle

100

What is the part of a circle that goes from the center to the edge?

Radius

200

What is the part of a circle that goes from edge to edge through the center? 

Diameter

300

A circle has a diameter of 12 inches. What is the radius?

6 inches

400

A circle has a radius of 5.5 inches. What is the diameter? 

11 inches

500

A ferris wheel travels 120 feet to make one full rotation. What part of a circle is the ferris wheel's rotation? 

Circumference

Area

100

What does the ² in the formula A = πr² stand for? 

Squared

200

A circle has a radius of 10 inches. What is the area? 

314 square inches

300

A circle has a diameter of 14 inches. What is the area? 

153.86 square inches

400

A cookie cake is 5.5 inches from center to edge. How many square inches of cake are there? Round to the nearest whole number (no decimal)

95 square inches

500

Circle A has a radius of 4 inches. Circle B has a radius of 5 inches. How many square inches greater is the area of Circle B? 

28.26 square inches

Circumference

100

How do you use the radius of the circle to find the circumference? (hint: What do you multiply?)

2 x π x r

200

A circle has a diameter of 14 inches. What is the circumference? 

43.86 inches

300

A circle has a radius of 9 inches. What is the circumference?

56.52 inches

400

A motorcycle tire is 21 inches from edge to edge. What is the circumference? 

65.94 inches

500

James is running one lap around a circular track, while Julia decides to run across the diameter of the track. If the diameter of the track is 120 feet, how much further did James travel? 

256.8 feet

Backwards Circumference

100

When you are given circumference and you are solving for diameter, what do you do instead of multiplying by pi? 

Divide by pi

200

If the circumference is 12.56 inches, what is the diameter? 

4 inches

300

A steering wheel has a circumference of 50.24 inches. What is the diameter of the wheel? 

16 inches

400

A cake has a circumference of 25.12 inches. What is the diameter? 

8 inches

500

A giant cookie has a circumference of 43.96 inches. What is the radius? 

7 inches

Extra

100

Which number is larger for any circle, radius or diameter?

Diameter

200

Speed round! You have thirty seconds to pick the right answer. If a circle has a diameter of 7 inches, what is the circumference? 

A. 10.99 inches

B. 21.98 inches

C. 43.96 inches

B. 21.98 inches

300

A figure skater makes two laps around the ice rink. If the rink has a diameter of 50 feet, how far did she travel? 

314 feet

400

For her art project, Kate paints three circles that each have a radius of 2.4 inches. How many square inches of paint will she need? 

54.26 square inches

500

DOUBLE POINTS! If the circumference of a circle is 18.84 inches, what is the area? 

28.26 square inches