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

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

What does "circumference" mean?

• Space a circle takes up
• Distance around a circle
• Line from one side of a circle to another
• Line from center of circle to side

Does this picture show the diameter or radius of a circle?

• Diameter
• Radius

Does this picture show the diameter or radius of a circle?

• Diameter
• Radius

Steven purchases a bowl. The diameter of the bowl is 14 cm. What is the circumference of the bowl?

• 28 cm
• 43.98 cm
• 87.96 cm
• 7 cm

Cynthia wants to buy a round photo frame for her brother. The radius of the photo frame is 9 cm. What is the photo frame’s diameter?

• 28.26 cm
• 56.52 cm
• 4.5 cm
• 18 cm

What is the circumference of this circle?

• 3.14 cm 
• 37.7 cm
• 24 cm
• 68.4 cm

Find the circumference of a circle with a radius of 12.5 mm.

• 37.68mm
• 18.84mm
• 78.54mm
• none of the above