Euclid’s parallel postulate

Example · High school

Through a point not on a line, there is exactly one line parallel to the given line.

Terms

Term	This example	Why
postulate	✓	Euclid’s parallel postulate is a postulate, and so an axiom, because Euclidean geometry takes it as given without proof.
axiom	✓
assumption	✗	Euclid’s parallel postulate is not an assumption of a single result; dropping it gives non-Euclidean geometries.

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