Question

What is the formula for finding diameter from circumference

Answer 1

The equation for the circumference is 2*pi*radius
if you are given the circumference then divide both sides by pi
that is because the diameter is 2 times the radius
so you can rearrange the equation to
C = pi * 2 * r
C = pi * d
divide both sides by pi
C/pi = d

Hope this helps :)