Question

What is circumference of 15 inch diameter?

Answer 1

`47.1` `"in"`

Explanation:

The formula for finding the circumference of a circle is:

`2pir` or, since they gave you the diameter of your circle, we can simplify it to: `pid`

Plugging values into the equation, we get:
*(Remember: pi is approximately 3.14)

`pid rarr pi(15) rarr 3.14(15)`

Now multiply:
`3.14(15) = 47.1` `"in"`