Proposition: Prop. 9.02: Numbers whose Product is Square are Similar Plane Numbers

Euclid's Formulation

If two numbers make a square (number by) multiplying one another then they are similar plane numbers. * Let $A$ and $B$ be two numbers, and let $A$ make the square (number) $C$ (by) multiplying $B$. * I say that $A$ and $B$ are similar plane numbers. fig02e

Modern Formulation

(not yet contributed)

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