HG 31
A15. Hyperbolic Parallel Postulate. There are at least two lines parallel to a given line through a point not on the line.
T47. The sum of two angels of a triangle is less than or equal to their remote exterior angle.
T48. Let L be a line, P a point not on L, and Q a point on L; let a side of line PQ be given. Then there exists a point R of L, on the given side of PQ, such that angle PRQ is as small as we please.