half-disk
11Unit disk — For other uses, see Disc (disambiguation). An open Euclidean unit disk In mathematics, the open unit disk (or disc) around P (where P is a given point in the plane), is the set of points whose distance from P is less than 1 …
12Hard disk drive — Hard drive redirects here. For other uses, see Hard drive (disambiguation). Hard disk drive Mechanical interior of a modern hard disk drive Date invented 24 December 1954 [1] …
13Area of a disk — Part of a series of articles on the mathematical constant π …
14Poincaré disk model — Poincaré disc model of great rhombitruncated {3,7} tiling …
15Airy disk — Computer generated image of an Airy disk. The gray scale intensities have been adjusted to enhance the brightness of the outer rings of the Airy pattern …
16Poincaré half-plane model — Stellated regular heptagonal tiling of the model.In non Euclidean geometry, the Poincaré half plane model is the upper half plane, together with a metric, the Poincaré metric, that makes it a model of two dimensional hyperbolic geometry.It is… …
17History of hard disk drives — The commercial usage of hard disk drives began in 1956 with the shipment of an IBM 305 RAMAC system including IBM Model 350 disk storage [ [http://www.magneticdiskheritagecenter.org/MDHC/MILESTONE/Emerson%20Pugh%20talk.pdf Ramac History May2005 ] …
18Upper half-plane — In mathematics, the upper half plane H is the set of complex numbers with positive imaginary part y: The term is associated with a common visualization of complex numbers with points in the plane endowed with Cartesian coordinates, with the Y… …
19Counterexamples in Topology —   Author(s) Lynn Arthur Steen J. Ar …
20Torquetum — The torquetum or turquet is a medieval astronomical instrument designed to take and convert measurements made in three sets of coordinates: Horizon, equatorial, and ecliptic. In a sense, the Torquetum is an analog computer.The first torqueta is… …
