65 x pi = 204.2cm to one decimal place.
If that's the diameter, you can multiply that by pi (which is approximately 3.14), to get the circumference.
The circumference of a ball is C = diameter times pi. pi = 3.14159 ... So you get the circumference C = 27.4889 inches.
Circumference of pool ball: 2*pi = 6.283 inches rounded to 3 decimal places
Circumference = π x DiameterC= 3.14159 x 14C= 43.98 cm
The quickest way would be to actually measure it!Another way is to find how high/wide the ball is. This has to be done very accurately. Yoy could use parallel wooden boards (be careful not to squash the ball!The multiply the width/height of the ball by 3.14159265 (Pi).The formula is Pi x d (diameter) = circumference. A ball that is 30 cms in diameter will have a circumference of 94.248 cms.