That wasn't the question, though. Pi is the ratio between circumference and diameter of a perfect circle, whether or not you can create a perfect circle in your universe. We can't even create one in ours, and yet pi still "exists" here. Undoubtedly, wiggly-space mathematicians would also have a conception of pi, though it might be as esoteric to them as toroidial universes are to us.

To put that another way: Math has very simple axioms (e.g. set theory), and everything else derives from them. What theories can be proven from those axioms in this universe, can be proven from those axioms in any universe (and a universe that doesn't obey those axioms likely wouldn't "function" as a universe—it wouldn't have any reason to be causal, for example.) The maths describing a particular universe is its physics, which do change from universe to universe—however, those physics are all just different subsets of the set of mathematical physical models—which are, themselves, a subset of the mathematical theories provable from the axioms.