Question

What is the circumference of a circle with a diameter of 16 in?

Answer 1

`16pi`

Explanation:

We have that the circumference C is `pi*2r` or `pi*d`, that's because `pi` was defined as the ratio between the circumference and the diameter. So, axiomatically:

`C/d = pi`, therefore `C = pi*d`

Answer 2

`C=50. "in"`

Explanation:

The formula for calculating the circumference of a circle is `C=pi * d`, where `pi` is `3.1415...` and `d` is the diameter.

`C=pi * 16"in"=50.265482457437 "in"=50. "in"` (with two significant figures)