KoG, Vol. 16. No. 16., 2012.
Original scientific paper
Universal Hyperbolic Geometry IV: Sydpoints and Twin Circumcircles
Norman John Wildberger
orcid.org/0000-0003-3503-6495
; School of Mathematics and Statistics UNSW, Sydney, Australia
Ali Alkhaldi
; School of Mathematics and Statistics UNSW, Sydney, Australia
Abstract
We introduce the new notion of sydpoints into projective triangle geometry with respect to a general bilinear form. These are analogs of midpoints, and allow us to extend hyperbolic triangle geometry to non-classical triangles with points inside and outside of the null conic. Surprising analogs of circumcircles may be defined, involving the appearance of pairs of twin circles, yielding in general eight circles with interesting intersection properties.
Keywords
universal hyperbolic geometry; triangle geometry; projective geometry; bilinear form; sydpoints; twin circumcircles
Hrčak ID:
96187
URI
Publication date:
30.1.2013.
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