Question

What is the formula that relates circumference and radius?

A. C = 2r
B. C = 2/r
C. C = 2D
D. C + 2 = r

Answer 1

All the options are incorrect, if you're talking about circle! which is most common
C = 2πr..... It is the relation for Circle's if you're considering something else, then, please mention!

Answer 2

The formula that relates circumference and radius is
`C=2\pi r`.

Explanation:

The circumference of a circle is calculated by the formula

`C=2\pi r`

Where,

C is circumference of the circle.

r is radius of the circle.

π is 22/7 or 3.14.

In the given options π is not missing. So, all the given options are incorrect.

Therefore the formula that relates circumference and radius is
`C=2\pi r`.