Circles

What is the formula for circumference of a circle given the diameter?

• C = π r
• C = 2 π r
• C = π d
• C = 2 π d

If the area of a circle is 25 π in² , then the diameter is?

• 10 in
• 5 in
• 25 in
• pi in

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

• diameter
• radius
• π
• center

The distance across a circle through its center is called the _____.

• diameter
• radius
• π
• center

A _____ is half of a circle.

• circumference
• pi
• semicircle
•  composite figure

If you are given the diameter, how can you calculate the radius?

• Multiply the diameter by 2
• Divide the diameter by 2
• Add 2 to the diameter
• Subtract 2 from the diameter

Which segment is the diameter?

• AC
• BD
• LM
• CE

Which segment is a radius?

• LM
• DC
• BD
• ML

If the area of circle is 100 π , find the radius of the circle.

• 10 π
• 10
• 50
• 50 π

The definition of a circle is

• set of all points in a plain that are the same distance from a point called the center

• the distance around a share

• a large figure

• a pizza, orange, plum, or watermelon