Revision as of 19:25, 19 December 2020 edit Hammersoft (talk \| contribs) Administrators 94,596 edits rv to stable Tag: Manual revert ← Previous edit		Revision as of 16:58, 21 March 2021 edit undo 91.215.142.82 (talk) Why speak about specific models? Right angles can be recognized in every model, or synthetically without any model Next edit →
Line 3: In [[hyperbolic geometry]], two lines may intersect, be '''ultraparallel''', or be [[limiting parallel]]. ~~In conformal models of the [[hyperbolic plane]], such as the Poincaré models, [[right angle]]s may be recognized between intersecting lines. In such models, the~~The '''ultraparallel theorem''' states that every pair of (distinct) ultraparallel lines has a unique common [[perpendicular]] (a hyperbolic line which is perpendicular to both lines). ==Hilbert's construction==

Ultraparallel theorem: Difference between revisions