Circumference of Circles and Converse

If the diameter of a circle is 65 m, what is the circumference?

• 204.1 m

• 20.41 m

• 102.05 m

• 102.5 m

What does d represent in the formula:

C = π·d

• diameter

• radius

• pi

• 3.14

What number represents π?

• 31.4

• 4.13

• 3.14

• 34.1

Which expression could be used to find the approximate circumference of the quilt piece?

• 2(pi)16

• 2(pi)8

• 2(8)

• 2(4)

Which best approximates the circumference of the outer ring of this clip?

• 27cm

• 18cm

• 9cm

• 3cm

What is the circumference?

• 36

• 18pi

• 108pi

• 36pi

The distance around a circle; much like the perimeter of a rectangle.

• perimeter

• diameter

• circumference

• radius

Alex has trained his puppy, Popper, to jump through a ring. According to Alex's measurements and calculations, the ring has a diameter of 3.5 feet. What is the ring's circumference (use 3.14 for pi)?

• 11.32 ft

• 12.25 ft

• 10.99 ft

• 8.75 ft

The distance around a circular track is 31.4 yards. What Is the radius of the track?

• r=10

• r=5

• r=98.6

What is the diameter?

• 8

• 16

• 10

• 4