Proposition: Prop. 11.24: Opposite Planes of Solid contained by Parallel Planes are Equal Parallelograms
(Proposition 24 from Book 11 of Euclid's “Elements”)
If a solid (figure) is contained by (six) parallel planes then its opposite planes are both equal and parallelogrammic.
* For let the solid (figure) $CDHG$ have been contained by the parallel planes $AC$, $GF$, and $AH$, $DF$, and $BF$, $AE$.
* I say that its opposite planes are both equal and parallelogrammic.
Modern Formulation
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Table of Contents
Proofs: 1
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Proofs: 1 2 3 4 5 6
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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