Circumference of a Circle with Exact Pi

Find the circumference of Circle C.

Which of the following below must you always use Pi calculations for?

• to find the area and circumference of a circle

• to find the area of a rectangle

• to find the height of a square

• to find the length from one edge of a triangle to another

• to find the derivative of a function

Find the circumference of the circle shown. (HINT: Circumference = 2πr)

• 9π in.

• 4.5π in.

• 81π in.

• 28.26π in.

• 18π in.

What is the approximate value of Pi in FRACTION form?

• 3 ⁄ 14

• 14 ∕ 4

• 34 ∕ 11

• 22 ∕ 7

• 7 / 22

Pi is the ratio of a circle’s _________ to _________.

• radius / diameter

• circumference / diameter

• area / circumference

• circumference / radius

• diameter / radius

_____________ is the distance around the circle.

• circumference

• center

• radius

• diameter

• perimeter

A bicycle tire has a radius of 15 inches. How far does the bike travel when it makes 4 full rotations?

• 94.2 in

• 376.8 in

• 188.4 in

• 567.2 inches

Answer explanation

15*2 to find diameter. Diameter Pi to find circumference. Circumference * 4 to find distance traveled in 4 rotations.