Area and Circumference Review

What is the area of the circle?

• 15.7 cm²
• 78.5 cm²
• 31.4 cm²
• 5 cm²

What is the circumference of the circle?

• 25.12 in.
• 12.56 in.
• 50.24 in.

Sally tried to solve for the area of circle. Her work is shown. What mistake did Sally make.

• Sally squared π incorrectly.

• Sally multiplied the π and radius incorrectly.

• Sally used diameter instead of the radius.

• No mistake. Sally solved the problem correctly.

What is the radius of this circle?

• 18
• 36
• 9
• 8

What is the diameter of this circle?

• 3.5 m
• 3 m
• 5 m
• 7 m

What is the radius of this circle?

• 18 in
• 10 in
• 9 in
• 8 in

The radius is 8 inches.  What is the circumference?

• 50.24 inches
• 25.12 inches
• 12.56 inches
• 200.96 inches

What is the circumference of a circle with a radius of 21 cm?

• 131.9 cm
• 121.9 cm
• 111.9 cm
• 141.9 cm

What is the area of this circle?

• 16π
• 8π
• 4π
• 16π²

A DVD has a diameter of 15 millimeters. Which equation would help you determine the circumference?

• c = 15π
• C = 2π15
• c = 15 ÷ π
• c = 15 π