Topics
Cartesian half planes
Poincaré half planes
The Euclidean plane satisfies the Plane Separation Axiom (PSA)
The Taxicab plane satisfies PSA
The Poincaré plane satisfies PSA
Drawings showing how Poincaré plane satisfies PSA
Discussing concepts from Section 4.2 of Millman & Parker, Geometry: A Metric Approach with Models, 2nd Edition