I am trying to design a program that would allow any robot to do a half-circle, and would need to use the number PI. I am wondering if it is in the library of RobotC or if I should give it an approximation.

Hmmm. Sounds like an intetesting program. Will it take number of motors and wheel base into account?

Not sure how many digits RobotC can handle, but I should think that a variable set to 3.1416 would be exact enough for anything you would need.

Good luck!

And that is still an approximation

It is, but using 3 or 3.2 in robot calculations will get you close enough. You are moving 8’.