# Math Help - [SOLVED] Circumference of Hyperbolic circle

1. ## [SOLVED] Circumference of Hyperbolic circle

how do you get the hyperbolic circumference of a circle given a euclidian circle with center (h,k) and radius r.

[please don't give me the formula of circumference of hyperbolic circle.]

Given a euclidian circle ...it's easy to find its hyperbolic center and the radius but i'm not sure how the circumference translates to hyperbolic geometry.

thanks

2. For a euclidean circle with center (h,k) and radius r, the hyperbolic center would be (H,K) where H=h and K=sqrt(k^2-r^2) and the radius would be 1/2(ln((k+r)/(k-r))) After you find the hyperbolic radius plug into the formula 2pisinh(r) and you will get the hyperbolic circumference.