circumference of a circle

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr, where C is circumference, d is diameter, and r is radius.

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 diameter is twice the radius (d = 2r).

Front

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

Back

C = 2π(7) = 14π inches or approximately 43.98 inches.

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

What is the diameter of a circle with a radius of 4 meters?

Back

8 meters.

Front

What does the term 'circumference' refer to?

Back

The distance around the circle.

Front

If the radius of a circle is 3 feet, what is the circumference?

Back

C = 2π(3) = 6π feet or approximately 18.85 feet.

Front

What is the diameter of a circle with a circumference of 12.56 cm?

Back

4 cm (using d = C/π).

Front

What is the radius of a circle with a diameter of 16 inches?

Back

8 inches.