English

On the equivalence of Playfair's axiom to the parallel postulate

History and Overview 2019-03-15 v1 Metric Geometry

Abstract

We show that the classical equivalence of Euclid's parallel postulate and Playfair's axiom collapses in the absence of triangle congruence. In particular, we construct a non-SAS geometry that models the Playfair axiom but not the parallel postulate.

Keywords

Cite

@article{arxiv.1903.05233,
  title  = {On the equivalence of Playfair's axiom to the parallel postulate},
  author = {Elizabeth T. Brown and Emily Castner and Stephen Davis and Edwin O'Shea and Edouard Seryozhenkov and AJ Vargas},
  journal= {arXiv preprint arXiv:1903.05233},
  year   = {2019}
}

Comments

5 pages, 3 figures