Circumference of a Circle

What is the formula for finding the circumference of a circle?

• C = r²

• C = rd

• A = π·r²

• C = π·d

What is the circumference of a circle?

• the distance around a circle

• the area of a circle

• halfway through a circle

• a line through the center of a circle

Find the circumference of the circle.

• 18.8 cm

• 113 cm

• 37.7 cm

• 452.2 cm

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

what is the circumference of this circle ?

• 3.14 cm 

• 37.68 cm

• 24 cm

• 68.4 cm

What is the circumference?

• 36

• 18pi

• 108pi

• 36pi

• 31.4 cm

• 62.8 cm

• 15.7 cm

• 28.26 cm

• F

• G

• H

• J

HINT: Use the formula chart! Is the radius or diameter labeled?

• a

• b

• c

• d

What is the definition of the number π (pi)?

• 3.14

• The ratio of the circumference of a circle to its diameter

• The ratio of a circles diameter to its circumference

• The ratio of the radius of a circle to its diameter