Non-Euclidean geometry that are both perpendicular to a third line: Euclidean geometry, named after the Greek mathematician Euclid, includes some of the oldest known mathematics, and geometries that deviated from this were not widely accepted as legitimate until the 19th century. The debate that eventually led to the discovery of the non-Euclidean geometries began almost as soon as Euclid's work "Elements" was written. In the "Elements", Euclid began with a limited number of assumptions (23 definitions, five common notions, and five postulates) and sought to prove all the other results (propositions) in the work. The most notorious of the postulates is often
Antiochus (father of Seleucus I Nicator) Antiochus (father of Seleucus I Nicator) Antiochus (Greek: Ἀντίοχος; fl. 4th century BC) was a Macedonian man who lived during the time of Philip II of Macedon (ruled 359-336 BC). He originally came from Orestis, Macedonia. Antiochus served as an officer under Philip II, and gained distinction as a military general. Antiochus was from an upper noble family. His father was probably called Seleucus, his brother was called Ptolemy and he probably had a nephew called Seleucus. Antiochus married a Macedonian woman called Laodice and in about 358 BC Laodice bore Antiochus a son Seleucus I Nicator, who became a