Circumference

Front

What is the formula for calculating the circumference of a circle?

Back

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

Front

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

Back

C = 2π(5) = 10π cm or approximately 31.42 cm.

Front

What does 'circumference' refer to in geometry?

Back

The circumference is the distance around a circle.

Front

How is the diameter of a circle related to its radius?

Back

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

Front

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

Back

r = C / (2π) = 31.4 / (2π) ≈ 5 cm.

Front

What is the circumference of a circle with a diameter of 12 inches?

Back

C = πd = π(12) = 12π inches.

Front

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

Back

Circumference is related to the perimeter, while area measures the space within the circle. They are calculated using different formulas.

Front

If the circumference of a circle is 50 cm, what is the diameter?

Back

d = C / π = 50 / π ≈ 15.92 cm.

Front

What is the circumference of a circle with a radius of 8 in terms of Pi?

Back

C = 2π(8) = 16π.

Front

How do you convert circumference to radius?

Back

r = C / (2π).