Question

What would be the best estimate of the circumference if a circle diameter is 3 inches?

Answer 1

9

Explanation:

The formula for circumference is `C = pid`
If the diameter is 3 inches, then the circumference would be `3pi`.

`pi` is an irrational number 3.14159....`" "`(it never ends)
To estimate using mental math, use 3 as the value for `pi`. So `(3)(3) = 9`

If you are not allowed to use calculators, most instructors recommend using 3.14 as the `pi` value and calculating manually.