Diameter and Radius of Circles

What is the formula to calculate the diameter of a circle?

• radius * 2

• radius + radius

• radius / 2

• 2 * radius

If the radius of a circle is 5 cm, what is its diameter?

• 3 cm

• 7 cm

• 15 cm

• 10 cm

What is the relationship between the radius and diameter of a circle?

• The radius is twice the length of the diameter.

• The radius and diameter are equal in length.

• The diameter is twice the length of the radius.

• The diameter is half the length of the radius.

If the diameter of a circle is 12 cm, what is its radius?

• 10 cm

• 8 cm

• 6 cm

• 4 cm

What is the diameter of a circle with a radius of 8 cm?

• 10 cm

• 20 cm

• 12 cm

• 16 cm

Explain how to find the radius of a circle if the diameter is given.

• Multiply the diameter by 2

• Divide the diameter by 2

• Subtract the diameter from 2

• Add the diameter to 2

If the diameter of a circle is 20 cm, what is its radius?

• 15 cm

• 10 cm

• 25 cm

• 5 cm

What is the diameter of a circle with a radius of 10 cm?

• 20 cm

• 25 cm

• 30 cm

• 15 cm

How does the diameter of a circle compare to its radius?

• The diameter is three times the length of the radius.

• The diameter is twice the length of the radius.

• The diameter is equal to the length of the radius.

• The diameter is half the length of the radius.

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

• 8 cm

• 15 cm

• 12 cm

• 3 cm