Axiom: 1.2: Segment Extension

(Postulate 2 from Book 1 of Euclid's “Elements”)

And to produce a finite straight line continuously in a straight line.

Modern Formulation

A segment may be extended from any length to a longer segment, a ray, or a straight line.

Parts: 1
Proofs: 2
Propositions: 3

Thank you to the contributors under CC BY-SA 4.0!



Adapted from CC BY-SA 3.0 Sources:

  1. Callahan, Daniel: "Euclid’s 'Elements' Redux" 2014

Adapted from (Public Domain)

  1. Casey, John: "The First Six Books of the Elements of Euclid"

Adapted from (subject to copyright, with kind permission)

  1. Fitzpatrick, Richard: Euclid's "Elements of Geometry"