Circle's Diameter and Circumference

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

• center
• diameter
• radius

• center
• diameter
• radius

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

• Radius

• Diameter

What is the circumference of a circle with a radius of 54 m?

• 339.12 m

• 169.56 m

• 84.78 m 

A cruise ship has a large, circular window. It has a diameter of 6 meters. What is the window's approximate circumference?

• 3 m 

• 9.42 m

• 12 m

• 18.84 m

If my diameter is 19 inches, what is my radius?

• 38 inches

• 9.5 inches

• 59.66 inches

• 119.32 inches

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 circumference (to the nearest whole number)

• 88 in

• 44 in

• 116 square in

• None of the above