circumference of a circle

Front

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

Back

Circumference = π × diameter (C = πd) or Circumference = 2 × π × radius (C = 2πr)

Front

What is the value of π (pi) commonly used in calculations?

Back

Approximately 3.14.

Front

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

Back

5 cm.

Front

What is the relationship between diameter and radius?

Back

The radius is half of the diameter.

Front

If a circle has a circumference of 31.4 cm, what is its diameter?

Back

10 cm (using C = πd, d = C/π).

Front

True or False: A circle can have more than one radius.

Back

False.

Front

What is the circumference of a circle with a radius of 7 cm?

Back

43.96 cm (using C = 2πr).

Front

If the diameter of a circle is 4 feet, what is the circumference?

Back

12.56 feet (using C = πd).

Front

What does the term 'circumference' refer to?

Back

The distance around the circle.

Front

If the radius of a circle is doubled, what happens to the circumference?

Back

It also doubles.