Circumference of a Circle

Front

What is the formula for the circumference of a circle?

Back

C = π·d or C = 2·π·r

Front

What does 'C' represent in the formula C = π·d?

Back

Circumference of the circle.

Front

What does 'd' represent in the formula C = π·d?

Back

Diameter of the circle.

Front

What does 'r' represent in the formula C = 2·π·r?

Back

Radius of the circle.

Front

What is the approximate value of π (pi)?

Back

3.14

Front

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

Back

31.4 cm (C = π·d = 3.14·10)

Front

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

Back

31.4 cm (C = 2·π·r = 2·3.14·5)

Front

How do you convert diameter to radius?

Back

Radius = Diameter / 2.

Front

How do you convert radius to diameter?

Back

Diameter = Radius × 2.

Front

What is the circumference of a circle with a diameter of 20 cm?

Back

62.8 cm (C = π·d = 3.14·20)