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Proposition: 6.21: Similarity of Polygons is Transitive

(Proposition 21 from Book 6 of Euclid's “Elements”)

(Rectilinear figures) similar to the same rectilinear figure are also similar to one another.

• Let each of the rectilinear figures $A$ and $B$ be similar to (the rectilinear figure) $C$.
• I say that $A$ is also similar to $B$.

Modern Formulation

The similarity of rectilinear figures is transitive.

Table of Contents

Proofs: 1

Mentioned in:

Proofs: 1 2 3 4

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References

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", https://proofwiki.org/wiki/Main_Page, 2016