Attention math people

[Cornpatch MO]

What is the formula to find the diameter of a circle , when the circumference is known?
I want to know my harnonic balancer diameter, and the belt pulley is in the way. I shoulda paid more attention in math class!..A= pi r squared...................MO

 

[OH71RRunner]

Diameter = circumference divided by pi.
Pi is 3.1415

 

[Mike67]

Pi r round....cake are square....

 

[FJ6AAR]

Corn bread are square too!