The circumference formula of a circle is obtained by multiplying the diameter by pi(π). To recall, the circumference of a closed curve or circular object is the distance around its edge. The circumference of a circle has special importance in geometry and trigonometry.

## Formula to Find Circumference

The Circumference Formula requires either the radius or the diameter of the circle for its calculation.

Circumference of a Circle | C = 2πr = πd |

Where,

- C is the circumference of the circle.
- d is the diameter of the circle.
- r is the radius of the circle.

### Circumference Formula in Terms of Area

C = 2√(πA) |

### Solved Examples

**Question: **The radius of a circle is 2 inches. What is the circumference of the circle?

** Solution: **

Given,

Radius of the circle = r = 2 inches

Circumference of the circle = 2πr = 2 × π × 2 inches = 12.57 inches