WoodinMath Circle Vocabulary and Circumference

Name the straight line that touches a circle at two points, as well as it's center.

• radius

• diamater

• chord

• string

π is the Greek letter pi.

What is the value of the first 3 digits of π?

• 314

• 31.4

• 3

• 3.14

A radius is a straight line from the center of a circle to one point on the circle.

What color is the radius in the picture shown?

• red

• blue

• green

• yellow

Which is the best definition of circumference?

• A circle

• The distance from the center to the circle

• The distance around the circle

• 3.14 x the radius or the circle

C is Circumference, π=3.14, d = diameter

C= π • d

What is the circumference if d = 10 feet?

• 31.4 feet

• 3.14 feet

• 31.4 square feet

• 31.4 inches

Round π to the nearest whole number.

π is closest to:

• 314

• 31

• 3

• 4

In the picture, which is the longest measurement?

• radius

• diameter

• circumference

• center

In the picture, which is the shortest measurement?

• Circumference

• Radius

• Diameter

• Kangaroo

The diameter of a wheel is 20 cm. A good ROUNDED ESTIMATE for the circumference would be:

• 6 cm

• 60 cm

• 600 co

• 3.14 cm

If a circle has a circumference of 30 cm, a good ROUNDED ESTIMATE of the diameter would be:

• 30 CM

• 10 CM

• 10 CM SQUARED

• 100 CM