Circle Properties and Calculations

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

• 10 cm

• 7 cm

• 5 cm

• 3 cm

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

• 15 cm

• 8 cm

• 10 cm

• 12 cm

Calculate the circumference of a circle with a radius of 7 cm. (Use π = 3.14)

• 21.98 cm

• 43.96 cm

• 31.40 cm

• 50.24 cm

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

• The radius is twice the diameter.

• The diameter is half the radius.

• The diameter and radius are equal.

• The diameter is twice the radius.

If the circumference of a circle is 31.4 cm, what is its radius? (Use π = 3.14)

• 5 cm

• 3 cm

• 7 cm

• 10 cm

Determine the diameter of a circle with a circumference of 62.8 cm. (Use π = 3.14)

• 15 cm

• 25 cm

• 20 cm

• 30 cm

If a circle has a radius of 4 cm, what is its area? (Use A = πr²)

• 12π cm²

• 20π cm²

• 8π cm²

• 16π cm²

What is the circumference of a circle with a diameter of 12 cm? (Use π = 3.14)

• 37.68 cm

• 31.42 cm

• 25.12 cm

• 40.00 cm

Explain the significance of π in circle calculations.

• π has no relation to the properties of circles.

• π is only relevant for calculating the diameter of a circle.

• π is significant in circle calculations as it relates the circumference and area to the radius.

• π is used to measure the angles in a triangle.

If the radius of a circle is doubled, how does the circumference change?

• The circumference remains the same.

• The circumference doubles.

• The circumference decreases by half.

• The circumference triples.