A curve unique to hyperbolic geometry, also called an "equidistant curve", consisting of all the points that are a given perpendicular distance from a given line. In Euclidean geometry, this would simply be another line parallel to the first, but in hyperbolic geometry, parallel lines diverge. Two hypercycles will be congruent only if they have the same distance from their base lines. In the Poincare disk model of the hyperbolic plane, a hypercycle is represented by a circular arc that meets its base line at both ends; the angle with which this arc meets the unit circle is determined by the hypercycle's distance from its base line.