Basic Properties of Circles

What is the name for the distance from the center of a circle to its edge?

• Diameter

• Chord

• Radius

• Arc

If a circle has a radius of 6 cm, what is its diameter?

• 12 cm

• 18 cm

• 3 cm

• 9 cm

Which formula is used to find the area of a circle?

• A = 2πr

• A = πd

• A = 2πd

• A = πr²

A circle has a circumference of 31.4 cm. What is its diameter? (Use π = 3.14)

• 10 cm

• 15 cm

• 3.14 cm

• 20 cm

What is a chord in a circle?

• A line from center to edge

• A line outside the circle

• A segment with endpoints on the circle

• A 180° arc

If the diameter of a circle is 10 inches, what is the area? (Use π = 3.14)

• 31.4 in²

• 78.5 in²

• 25 in²

• 100 in²

What makes a tangent line unique?

• It crosses through the circle

• It touches the circle at only one point

• It forms a triangle

• It passes through the center

A circular rug has a radius of 2.5 ft. What is its circumference? (π = 3.14)

• 7.85 ft

• 6.25 ft

• 12.5 ft

• 15.7 ft

How do you find the radius if you're only given the diameter?

• Multiply by 2

• Square the diameter

• Divide the diameter by 2

• Subtract 1

A circle has an area of 28.26 m². What is its radius? (π = 3.14)

• 3 m

• 4 m

• 5 m

• 6 m