Revision #228 → #1428 · back to history
addedNon-Euclidean geometry3576ced56150
addedPlayfair's postulatee753e9f37015
addedParallels in hyperbolic vs elliptic geometryc8f4e2ddc9cd
addedUltraparallelscc31ffea52de
addedEuclid's fifth (parallel) postulatedbc6fc45edba
addedEuclid's first four postulatesb58b95407054
addedKhayyam's postulateeaefe2b76895
addedVitale's equidistance resultb874b5bc5c80
addedLambert's angle-sum and area resulta7b218c6ca70
addedAbsolute geometryd57ab7fe18c1
addedBirkhoff's axiomecbcac0c968c
addedFirst 28 propositions hold in absolute geometry2d1b53142e57
addedHyperbolic parallel axiomba058d872f67
addedElliptic parallel axiom7a655bbeb8bb
addedModels of non-Euclidean geometryf3321d6b7fc6
addedEuclidean model (flat plane)966a7c930e1f
addedPseudosphere model of hyperbolic geometry528cb57548f4
addedSphere model of elliptic geometryefa972627776
addedSphere as real projective plane model1574792e79bd
addedElliptic model: lines always intersect40559a2b1580
addedKlein modelefa4c224b8b5
addedEquiconsistency of hyperbolic and Euclidean geometry1a501abf1fbf
addedHyperbolic model: infinitely many parallels488053967d64
addedEight three-dimensional geometries2d8ed3d6cce5
addedLambert quadrilaterald024a099d5ff
addedFourth angle of a Lambert quadrilateral4346da02bd20
addedRectangles exist only in Euclidean geometrya77cc27b6c82
addedSaccheri quadrilateral28282cb063ad
addedSummit angles of a Saccheri quadrilaterale50f1b728e16
addedSummit angle type by geometry842dc237e57b
addedTriangle angle sum by geometry92e158ec9a7e
addedDefect of a triangle1cd3b3348d12
addedSign of triangle defect by geometrydeac19844222
addedGeneralized complex numbers20af575c4864
addedEuclidean plane case8fdb8eb3780e
addedUnit circlef60937f5f351
addedSplit-complex numbera885aa5df10e
addedUnit hyperbola013ef89b29c4
addedDual number4baa99335159
addedNon-Euclidean angles via polar decompositiona87d8455f7c3
addedProper-time future submanifold is hyperbolic 3-spacef12024ea955c
addedHyperboloid model9f2a09bcf972
addedSplit-complex spacetime eventbd1f5e78c0d6
addedMultiplication as Lorentz boostfd7063b1c3cc
addedDual numbers and shear mappingb0e67a80b64a