**Dehn planes** — In geometry, Dehn constructed two examples of planes, a semi Euclidean geometry and a non Legendrian geometry, that have infinitely many lines parallel to a given one that pass through a given point, but where the sum of the angles of a triangle… … Wikipedia

**Dehn function** — In the mathematical subject of geometric group theory, a Dehn function, named after Max Dehn, is an optimal function associated to a finite group presentation which bounds the area of a relation in that group (that is a freely reduced word in the … Wikipedia

**Max Dehn** — Born November 13, 1878(1878 11 13) … Wikipedia

**List of mathematics articles (D)** — NOTOC D D distribution D module D D Agostino s K squared test D Alembert Euler condition D Alembert operator D Alembert s formula D Alembert s paradox D Alembert s principle Dagger category Dagger compact category Dagger symmetric monoidal… … Wikipedia

**Non-standard analysis** — Abraham Robinson Gottfried Wilhelm Leibniz argued tha … Wikipedia

**Hilbert's third problem** — The third on Hilbert s list of mathematical problems, presented in 1900, is the easiest one. The problem is related to the following question: given any two polyhedra of equal volume, is it always possible to cut the first into finitely many… … Wikipedia

**Small cancellation theory** — In the mathematical subject of group theory, small cancellation theory studies groups given by group presentations satisfying small cancellation conditions, that is where defining relations have small overlaps with each other. It turns out that… … Wikipedia

**Euclidean geometry** — geometry based upon the postulates of Euclid, esp. the postulate that only one line may be drawn through a given point parallel to a given line. [1860 65] * * * Study of points, lines, angles, surfaces, and solids based on Euclid s axioms. Its… … Universalium

**Knot theory** — A three dimensional depiction of a thickened trefoil knot, the simplest non trivial knot … Wikipedia

**Neue Galerie (Kassel)** — Südeingang während der aktuellen Sanierung Die Neue Galerie ist ein Museum in Kassel. Das Gebäude liegt an der sogenannten „Schönen Aussicht“ zwischen Rathaus und Karlsaue. Es wurde in den Jahren von 1871 bis 1877 nach Plänen des Architekten… … Deutsch Wikipedia