eAffineSyntheticAnalyticAlgebraicArithmeticDiophantineDifferentialRiemannianSymplecticDiscrete differentialComplexFiniteDiscrete/CombinatorialDigitalConvexComputationalFractalIncidence ConceptsFeaturesDimensionStraightedge and compass constructionsAngleCurveDiagonalOrthogonality (Perpendicular)ParallelVertexCongruenceSimilaritySymmetryZero-dimensionalPointOne-dimensionalLinesegmentrayLengthTwo-dimensionalPlaneAreaPolygonTriangleAltitudeHypotenusePythagorean theoremParallelogramSquareRectangleRhombusRhomboidQuadrilateralTrapezoidKiteCircleDiameterCircumferenceAreaThree-dimensionalVolumeCubecuboidCylinderPyramidSphereFour- / other-dimensionalTesseractHypersphereGeometersby nameAidaAryabhataAhmesAlhazenApolloniusArchimedesAtiyahBaudhayanaBolyaiBrahmaguptaCartanCoxeterDescartesEuclidEulerGaussGromovHilbertJyeṣṭhadevaKātyāyanaKhayyámKleinLobachevskyManavaMinkowskiMinggatuPascalPythago