Introduction E9F5FC Understandable FFFFFF Questions FFFFC0 Notes EEEEEE Software 
Theorems
Wildberger's key theorems
Concepts Incidence geometry Perspective maps lines to lines, conics to conics. Questions Do parallel lines going one way and going the other way meet at the same point at infinity? Or two different points at infinity? This is answered by considering a line as a vector space. So going around we get to the same line. But we have a different orientation. So the notion of orientation of a point becomes relevant. The line of infinity consists of oriented points. 
ProjectiveGeometryNaujausi pakeitimai 
Puslapis paskutinį kartą pakeistas 2018 gruodžio 30 d., 16:30
