Circles Review

Find the radius of a circle if the area is 201.1 mi²

• 10 mi

• 8mi

• 20 mi

• 5mi

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

• C = 15π

• A = π7.5²

• A = 15 ÷ π

• C = 7.5π

Randy’s circular garden has a radius of 1.5 feet. He wants to enclose the garden edging that costs $0.75 per foot. About how much will the edging cost? Use 3.14 for π!

• $9.42

• $7.07

• $3.53

• $4.71

What is the name of the line that goes from one end of the circle to the other and crosses the center point?

• Area
• Diameter
• Circumference
• Radius

Find the area of the circle.

• 9π cm²

• 36π cm²

• 3π cm²

• 2.25π cm²

_{Find the Circumference.}

• 5π in

• 10π in

• 25π in

• 2.5π in

A circle has a circumference of 16π cm.  Find the area of the circle.

• 64π cm²

• 256π cm²

• 1024π cm²

• 8π cm²

A circle has a circumference of 9π in. What is the area?

• 81π in²

• 4.5π in²

• 20.25π in²

• 9π in²

If the problem ask you to find the distance around a circle, which formula should you use?

• r = d/2

• d = 2r

• C = πd

• A = πr²

If the word problem is asking you to find the space inside the circle, which formula should you use?

• r = d/2

• d = 2r

• C = πd

• A = πr²