Proposition: Prop. 11.39: Prisms of Equal Height with Parallelogram and Triangle as Base
(Proposition 39 from Book 11 of Euclid's “Elements”)
If there are two equal height prisms, and one has a parallelogram, and the other a triangle, (as a) base, and the parallelogram is double the triangle, then the prisms will be equal.
* Let $ABCDEF$ and $GHKLMN$ be two equal height prisms, and let the former have the parallelogram $AF$, and the latter the triangle $GHK$, as a base.
* And let parallelogram $AF$ be twice triangle $GHK$.
* I say that prism $ABCDEF$ is equal to prism $GHKLMN$.

Modern Formulation
(not yet contributed)
Table of Contents
Proofs: 1
Mentioned in:
Proofs: 1 2
Thank you to the contributors under CC BY-SA 4.0!

- Github:
-

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