Proposition: 6.09: Construction of Part of Line

(Proposition 9 from Book 6 of Euclid's “Elements”)

To cut off a prescribed part from a given straight line. * Let $AB$ be the given straight line. * So it is required to cut off a prescribed part from $AB$.


Modern Formulation

It is possible to scale a yardstick (with an equidistant scale) of a given length $|AC|$ to the new length $|AB|.$

Proofs: 1

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



Adapted from (subject to copyright, with kind permission)

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

Adapted from CC BY-SA 3.0 Sources:

  1. Prime.mover and others: "Pr∞fWiki",, 2016