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

1 Answer
May 12, 2017

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.