Circles and Circumference and Pi

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 method could be used to find the radius of the circle formed by the pinwheel as it spins?

• Divide 9 inches by 2

• Divide 9 inches by pi

• multiply 9 inches by pi

• multiply 9 inches by 2

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

• 27cm

• 18cm

• 9cm

• 3cm

What is the radius?

• 18

• 72

• 38

• 14

What is the approximate numerical value of this sign?

• 3.11

• 3.14

• 4.13

• 6.28

What is Pi?

• Ratio of Circumference to diameter

• The distance around the outside of a circle

• The distance from one side of a circe to the other through the center

• The distance from the center of a circle to the outside

What is the circumference?

• 36

• 18pi

• 108pi

• 36pi

What is the radius?

• 28

• 15

• 26

• 13

A bicycle tire has a diameter of 27 inches. How far does the bike travel along the ground when the wheel rotates once? What is the circumference of this tire?

• 81

• 15.5

• 27

• 13

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

• perimeter

• diameter

• circumference

• radius