Covering common points
Source: Miklós Schweitzer 2018 P10
November 18, 2018
college contests
Problem Statement
In 3-dimensional hyperbolic space, we are given a plane and four distinct straight lines: the lines and are perpendicular to ; while the lines and do not intersect , and their distances from are equal. Denote by the surface of revolution obtained by rotating around . Show that the common points of and can be covered by two planes.