Thread: Hyperbolic Circumference

What is the hyperbolic circumference of a hyperbolic circle of hyperbolic radius r?

Not sure what to do with this one, but my professor gave us a couple things to consider:

By homogeneity, assume center is (0,0). In this case, note that hyperbolic circle is a Euclidean circle (centered at (0,0))

OK, I'm still having trouble with this. I know the answer should be something like 2pisin(hr) or something? We did it a little bit in class, using integrals and finding the length of a line or something. I'm still a little confused on how I am supposed to start attacking this problem.