Question

Which formula is used to find the circumference of a circle when the radius is given?
Responses

C=π2r


C=πr2


C=πr


C=π2d

Answer 1

The correct formula to find the circumference of a circle when the radius is given is:

**C = 2πr**

However, since this option is not in your provided responses, the closest correct option to circumference using the radius would be:

**C = πr**

but this is actually not the correct formula for circumference. The correct one involves the radius being multiplied by 2.

Nonetheless, the standard formula for circumference in terms of diameter (d) is:

**C = πd**

with \( d = 2r \).

So, be cautious in using the provided options, as none of them represent the full accurate formula.