Question

The number 3.14 is a rounded value of the mathematical quantity π. If you replace 3.14 with π, what is the exact formula for the circumference in terms of the diameter, d, and in terms of the radius, r?

Answer 1

The circumference C can be written as

`C = 2\pi r`

or as

`C = \pi d`

where each term is multiplied (example:
`2\pi r` means 2 times pi times r)