Circles Study Guide

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

• 38 inches

• 9.5 inches

• 59.66 inches

• 119.32 inches

Answer explanation

What is the diameter?

• 5 in
• 10 in
• 3.14 in
• 15.84 in

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

• Diameter
• Radius

What is the radius?

• 18
• 72
• 38
• 14

A bicycle tire has a diameter of 27 inches. What is the radius?

• 27pi
• 13.5
• 81
• 25pi

The distance around the wheel of a truck is 9.42 feet. What is the radius of the wheel?

• 3 feet
• 1.5 square feet
• 1.5 feet
• 29.58 square feet

A ball has a circumference of 9.42 cm. What is the diameter?

• 29.5788 cm
• 59.1576 cm
• 3 cm
• 1.5 cm

What is the circumference of a 12-inch pizza?

• 37.68 inches
• 18.84 inches
• 113.04 inches
• 432.16 inches

The Jones family wants to enclose their circular garden with a fence. What is the minimum length of fencing they need to buy?

• 56.25 ft

• 246.2 ft

• 365.56 ft

• 392.5 ft

Find the circumference with a diameter of 18.4 km. Use 3.14 for pi.

• 23.7 km

• 57.8 km

• 19.3 km

• 59.1 km