Circles

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

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. 

Is the red line a radius or diameter of the circle?

• Radius

• Diameter

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

To go from radius to diameter I need to do what?

• divide by 2

• multiply by 2

• multiply by 3.14

• divide by 3.14

To go from diameter to radius, what do I need to do?

• divide by 3.14

• multiply by 3.14

• multiply by 2

• divide by 2

A circular swimming pool is 21 feet in diameter.

How many feet around is the pool?

• 10.5 ft

• 42 ft

• 65.94 ft

• 131.95 ft

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

• 40ft

• 80ft

• 20ft

• 45ft

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

Determine the radius of the penny

• 59.66 mm

• 9.5 mm

• 38 mm

• 119.32 mm