The correct formula to find the circumference of a circle when the radius is given is:
C = 2πr
However, it seems that the exact option for this formula is not included in your responses. The option that is closest to the correct formula is the one that would be derived from the diameter, which is:
C = πd
where the diameter \(d\) is equal to \(2r\) (twice the radius).
So here’s the clarification:
- If you have the radius \(r\), the circumference is \(C = 2πr\).
- If the diameter \(d\) is given, the circumference can also be expressed as \(C = πd\).
Please ensure to check for the option that represents these relationships correctly.