Rewritten in vector notation.
A ratio that is invariant under projection.
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Desargues' Homology Theorem:
1) Pappus' Theorem: [url]http://www.geogebratube.org/material/show/id/35140[/url]
[b]→2) Vector notation[/b]
3) Desargues' Theorem: [url]http://www.geogebratube.org/material/show/id/35525[/url]
