"बीजगणित और ज्यामिति का कालक्रम" (अनुभाग) सम्पादित करें

== 19th century ==
* 1806 – [[Louis Poinsot]] discovers the two remaining [[Kepler-Poinsot polyhedra]].
* 1829 – [[Bolyai]], [[Carl Friedrich Gauss|Gauss]], and [[Nikolai Ivanovich Lobachevsky|Lobachevsky]] invent hyperbolic [[non-Euclidean geometry]],
* 1837 – [[Pierre Wantsel]] proves that doubling the cube and [[trisecting the angle]] are impossible with only a compass and straightedge, as well as the full completion of the problem of [[Constructible polygon|constructibility]] of regular polygons
* 1843 – [[William Rowan Hamilton|William Hamilton]] discovers the calculus of [[quaternion]]s and deduces that they are non-commutative,
* 1854 – [[Bernhard Riemann]] introduces [[Riemannian geometry]],
* 1854 – [[Arthur Cayley]] shows that [[quaternion]]s can be used to represent rotations in four-dimensional [[space]],
* 1858 – [[August Ferdinand Möbius]] invents the [[Möbius strip]],
* 1870 – [[Felix Klein]] constructs an analytic geometry for Lobachevski's geometry thereby establishing its self-consistency and the logical independence of Euclid's fifth postulate,
* 1873 – [[Charles Hermite]] proves that [[e (mathematical constant)|e]] is transcendental,
* 1878 – Charles Hermite solves the general quintic equation by means of elliptic and modular functions
* 1882 – [[Ferdinand von Lindemann]] proves that π is transcendental and that therefore the circle cannot be squared with a compass and straightedge,
* 1882 – Felix Klein invents the [[Klein bottle]],
* 1899 – [[David Hilbert]] presents a set of self-consistent geometric axioms in ''Foundations of Geometry''