Euclidean circle representing a perpendicular hyperbolic line
= Euclidean circle representing a perpendicular hyperbolic line
{c}
If $P$ is at hyperbolic distance $\rho$ from the origin, the Poincare-disc geodesic through $P$ perpendicular to $OP$ is represented by a Euclidean circle of radius $\operatorname{csch}\rho$ whose centre is at Euclidean distance $\coth\rho$ from the origin.