Here are the first four axioms of Euclidean Geometry

In Non-Euclidean Geometry we use the first four axioms of Euclidean geometry and then replace the fifth postulate (axiom) with an alternative version.

One version of the fifth postulate is that given a line and a point outside it, there is exactly one line through the point parallel with the given line. We therefore get two alternative versions:

Last change to this page
Full Page history
Links to this page
Edit this page
  (with sufficient authority)
Change password
Recent changes
All pages