Diameter and Radius of a Circle

What is the radius?

• 18

• 72

• 38

• 14

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

• Radius

• Diameter

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

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. 

What is the diameter of this circle?

• 3.5

• 3

• 5

• 7

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

• 28 cm

• 43.96 cm

• 87.96 cm

• 7 cm

Determine the radius of the penny

• 59.66 mm

• 9.5 mm

• 38 mm

• 119.32 mm

Alex has trained his puppy, Popper, to jump through a ring. According to Alex's measurements and calculations, the ring has a diameter of 3.5 feet. What is the ring's circumference (use 3.14 for pi)?

• 11.32 ft

• 12.25 ft

• 10.99 ft

• 8.75 ft

The diameter of a circle is 3 centimeters. What is the circumference?

• 11.5cm2

• 9.42 cm2

• unicorns are awsome

• 45.3 cm2

What is the radius of this circle?

• 18in

• 36in

• 9in

• 8in