diameter, radius and circumference

What is the radius?

• The distance from the center of the circle to an edge of the circle.

• The diameter of the circle divided by two.

• The circumference of the circle divided by pi.

• The distance around the circle.

If the diameter of a circle is 10 cm, what is the circumference?

• 25.0 cm

• 31.4 cm (using π ≈ 3.14)

• 20.0 cm

• 15.7 cm

What is the relationship between diameter and radius?

• Diameter = radius × 2

• Diameter = radius + 2

• Diameter = radius - 2

• Diameter = 2 × radius.

What does π represent?

• Approximately 3.14, it is the ratio of the circumference of a circle to its diameter.

• A mathematical constant representing the base of natural logarithms.

• The square root of 2, an important irrational number.

• The ratio of a circle's area to the square of its radius.

What is the diameter of a circle with a radius of 5 inches?

• 8 inches

• 10 inches

• 12 inches

• 6 inches

If the radius is 9.5 mm, what is the diameter?

• 17 mm

• 18 mm

• 19 mm

• 20 mm

If the circumference is 62.8 cm, what is the diameter?

• 15 cm

• 18 cm

• 20 cm

• 25 cm

What is the diameter of a penny if its radius is 9.5 mm?

• 15 mm

• 17 mm

• 19 mm

• 21 mm

What is the circumference of a circle?

• The measurement around the circle.

• The area inside the circle.

• The diameter of the circle.

• The radius of the circle.

If a circle has a circumference of 31.4 m, what is its radius?

• 3 m

• 4 m

• 5 m

• 6 m