Proposition: Prop. 10.107: Straight Line Commensurable With That Which Produces Medial Whole With Medial Area
(Proposition 107 from Book 10 of Euclid's “Elements”)
A (straight line) commensurable (in length) with a (straight line) which with a medial (area) makes a medial whole is itself also a (straight line) which with a medial (area) makes a medial whole.
* Let $AB$ be a (straight line) which with a medial (area) makes a medial whole, and let $CD$ be commensurable (in length) with $AB$.
* I say that $CD$ is also a (straight line) which with a medial (area) makes a medial whole.
Modern Formulation
(not yet contributed)
Table of Contents
Proofs: 1
Thank you to the contributors under CC BYSA 4.0!
 Github:

 nonGithub:
 @Fitzpatrick
References
Adapted from (subject to copyright, with kind permission)
 Fitzpatrick, Richard: Euclid's "Elements of Geometry"
Adapted from CC BYSA 3.0 Sources:
 Prime.mover and others: "Pr∞fWiki", https://proofwiki.org/wiki/Main_Page, 2016