Circumference of a Circle

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

• r^2

• 2 * r

• 2 * π * r

• π * r

If the diameter of a circle is 14 cm, what is its circumference? (Use π = 3.14)

• 44.56 cm

• 41.27 cm

• 43.96 cm

• 46.78 cm

What is the circumference of a circle with a radius of 5 cm? (Use π = 3.14)

• 10.5 cm

• 31.4 cm

• 15.7 cm

• 25.6 cm

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

• 15 cm

• 25 cm

• 20 cm

• 10 cm

Calculate the circumference of a circle with a radius of 8 cm. (Use π = 3.14)

• 60.24 cm

• 70.24 cm

• 50.24 cm

• 40.24 cm

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

• Circumference = π x Diameter

• Circumference = Diameter + π

• Circumference = Diameter^2

• Circumference = 2 x Diameter

If the circumference of a circle is 18.84 cm, what is its radius? (Use π = 3.14)

• 3 cm

• 4 cm

• 5 cm

• 6 cm

Explain how to find the circumference of a circle using the radius.

• Circumference = π * radius

• Circumference = 2 * π * radius

• Circumference = π * radius^2

• Circumference = 2 * radius

If the circumference of a circle is 62.8 cm, what is its radius? (Use π = 3.14)

• 5 cm

• 15 cm

• 20 cm

• 10 cm

Why is the value of π important when calculating the circumference of a circle?

• π is used to calculate the area of a triangle, not the circumference of a circle.

• π is a random number with no mathematical significance.

• π is the ratio of the circumference to the diameter of any circle.

• The value of π is only relevant for squares, not circles.