Definition: Def. 11.09: Similar Solid Figures
Similar solid figures are those figures contained by equal numbers of similar planes (which are similarly arranged).
Modern Formulation
Please refer to the modern definition of similarity, which is valid for Euclidean spaces of any dimension and for all geometrical objects contained in them.
Mentioned in:
Corollaries: 1 2 3
Proofs: 4 5 6 7 8 9 10 11 12 13 14
Propositions: 15 16 17 18 19
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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