Circumference of Circles

The distance halfway across the circle is called the...

• radius
• diameter
• circumference
• area

The distance from the center of the circle to any point on the circle is called the...

• radius

• diameter

• area

• circumference

If my radius is 10ft, what is my diameter?

• 20ft
• 5ft
• 31.4ft
• 62.8ft

A circle has a diameter of 36 ft. What is the radius?

• 18

• 72

• 14

What is the diameter of a circle if the radius is 8 cm?

• 8 cm

• 16 cm

• 4 cm

Find the radius of a circle who's diameter is 40 ft.

• 40ft
• 80ft
• 20ft
• 45ft

If my diameter is 6, my radius is ______.

If my radius is 15, my diameter is ____.

The diameter of a circle is:

• The measurement around the circle.
• The distance from an edge of a circle to another edge.
• The distance from the center of the circle to an edge of a circle
• The distance from an edge of a circle to another edge through the center. 

The radius of a circle is

• The measurement from the center of a circle to an edge of the circle.
• The measurement around the circle
• The measurement from and edge of the circle to another edge through the center
• A line perpendicular to the diameter of the circle