Vector intersection of two lines: [url]http://www.geogebratube.org/material/show/id/38384[/url]
Notes: [list] [*]Since u, v, w form a triangle, u x v = v x w = w x u So the unsigned product |(u x v)| can be replaced with any pair of the vectors u, v, w, in any order. [*]I used three vectors for algebraic simplicity. It is straightforward to unpack w into u and v. [/list] ________________ Tangency Problem of Appolonius: [url]http://www.geogebratube.org/material/show/id/34855[/url]