Pappus' Theorem 2

Written in vector notation...

The length of a vector v is √(v∙v) In the plane, (a x b) = |a||b|sin x, the determinant of a and b. (is probably an abuse of notation) In three dimensions (a x b) = c, a vector. Its length is |a||b|sin x, and it is perpendicular to both a and b. _______ Desargues' Theorem: 1) Pappus' Theorem: [url]http://www.geogebratube.org/material/show/id/35140[/url] [b]→2) Vector formula[/b] 3) Desargues' Theorem: [url]http://www.geogebratube.org/material/show/id/35525[/url]