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Eight-pointed Star
In geometry, an octagram is an eight-angled star polygon. The name ''octagram'' combine a Greek numeral prefix, '' octa-'', with the Greek suffix ''-gram''. The ''-gram'' suffix derives from γραμμή (''grammḗ'') meaning "line". Detail In general, an octagram is any self-intersecting octagon (8-sided polygon). The regular octagram is labeled by the Schläfli symbol , which means an 8-sided star, connected by every third point. Variations These variations have a lower dihedral, Dih4, symmetry: The symbol Rub el Hizb is a Unicode glyph ۞ at U+06DE. As a quasitruncated square Deeper truncations of the square can produce isogonal (vertex-transitive) intermediate star polygon forms with equal spaced vertices and two edge lengths. A truncated square is an octagon, t=. A quasitruncated square, inverted as , is an octagram, t=.The Lighter Side of Mathematics: Proceedings of the Eugène Strens Memorial Conference on Recreational Mathematics and its History, (1994 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a ''geometer''. Until the 19th century, geometry was almost exclusively devoted to Euclidean geometry, which includes the notions of point, line, plane, distance, angle, surface, and curve, as fundamental concepts. During the 19th century several discoveries enlarged dramatically the scope of geometry. One of the oldest such discoveries is Carl Friedrich Gauss' ("remarkable theorem") that asserts roughly that the Gaussian curvature of a surface is independent from any specific embedding in a Euclidean space. This implies that surfaces can be studied ''intrinsically'', that is, as stand-alone spaces, and has been expanded into the theory of manifolds and Riemannian geometry. Later in the 19th century, it appeared that geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flag Of Chile
A flag is a piece of fabric (most often rectangular or quadrilateral) with a distinctive design and colours. It is used as a symbol, a signalling device, or for decoration. The term ''flag'' is also used to refer to the graphic design employed, and flags have evolved into a general tool for rudimentary signalling and identification, especially in environments where communication is challenging (such as the maritime environment, where semaphore is used). Many flags fall into groups of similar designs called flag families. The study of flags is known as " vexillology" from the Latin , meaning "flag" or "banner". National flags are patriotic symbols with widely varied interpretations that often include strong military associations because of their original and ongoing use for that purpose. Flags are also used in messaging, advertising, or for decorative purposes. Some military units are called "flags" after their use of flags. A ''flag'' (Arabic: ) is equivalent to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellated Truncated Hexahedron
In geometry, the stellated truncated hexahedron (or quasitruncated hexahedron, and stellatruncated cube) is a uniform star polyhedron, indexed as U19. It has 14 faces (8 triangles and 6 octagrams), 36 edges, and 24 vertices. It is represented by Schläfli symbol t' or t, and Coxeter-Dynkin diagram, . It is sometimes called quasitruncated hexahedron because it is related to the truncated cube, , except that the square faces become inverted into octagrams. Even though the stellated truncated hexahedron is a stellation of the truncated hexahedron, its core is a regular octahedron. Orthographic projections Related polyhedra It shares the vertex arrangement with three other uniform polyhedra: the convex rhombicuboctahedron, the small rhombihexahedron, and the small cubicuboctahedron. See also * List of uniform polyhedra In geometry, a uniform polyhedron is a polyhedron which has regular polygons as faces and is vertex-transitive ( transitive on its vertices, isogonal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Polyhedron
In geometry, a star polyhedron is a polyhedron which has some repetitive quality of nonconvexity giving it a star-like visual quality. There are two general kinds of star polyhedron: *Polyhedra which self-intersect in a repetitive way. *Concave polyhedra of a particular kind which alternate convex and concave or saddle vertices in a repetitive way. Mathematically these figures are examples of star domains. Mathematical studies of star polyhedra are usually concerned with regular, uniform polyhedra, or the duals of the uniform polyhedra. All these stars are of the self-intersecting kind. Self-intersecting star polyhedra Regular star polyhedra The regular star polyhedra are self-intersecting polyhedra. They may either have self-intersecting faces, or self-intersecting vertex figures. There are four regular star polyhedra, known as the Kepler–Poinsot polyhedra. The Schläfli symbol implies faces with ''p'' sides, and vertex figures with ''q'' sides. Two of them have pen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branko Grünbaum
Branko Grünbaum ( he, ברנקו גרונבאום; 2 October 1929 – 14 September 2018) was a Croatian-born mathematician of Jewish descentBranko Grünbaum Hrvatska enciklopedija LZMK. and a professor at the in . He received his Ph.D. in 1957 from Hebrew University of Jerusalem< ...
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Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, which is maintained by the Unicode Consortium, defines as of the current version (15.0) 149,186 characters covering 161 modern and historic scripts, as well as symbols, emoji (including in colors), and non-visual control and formatting codes. Unicode's success at unifying character sets has led to its widespread and predominant use in the internationalization and localization of computer software. The standard has been implemented in many recent technologies, including modern operating systems, XML, and most modern programming languages. The Unicode character repertoire is synchronized with ISO/IEC 10646, each being code-for-code identical with the other. ''The Unicode Standard'', however, includes more than just the base code. Along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rub El Hizb
The Rub-el-Hizb ( ar, ربع الحزب, '), also known as the Islamic Star, is an Islamic symbol. It is in the shape of an octagram, represented as two overlapping squares. It has been found on a number of emblems and flags. The main purpose of this dividing system is to facilitate the recitation of the Quran. Etymology In Arabic, ''rubʻ'' means "one-fourth" or "quarter," while ''ḥizb'' (plural ''aḥzāb'') translates to "a group." Initially, it was used in the Quran, which is divided into 60 ''aḥzāb'' (groups of roughly equal length); Rubʿ el Hizb further divides each ḥizb in four. A ḥizb is one half of a juz'. History Investigations have shown that the Rub el Hizb symbol was originated from ancient petroglyphs in the Arabian desert. The symbol in question, consisting of two concentric circles with a defined punctual center, connected by eight radial sectors, is similar to the Islamic symbol when the two lines of the East-West orientation are combined, thus r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass Rose
A compass rose, sometimes called a wind rose, rose of the winds or compass star, is a figure on a compass, map, nautical chart, or monument used to display the orientation of the cardinal directions (north, east, south, and west) and their intermediate points. It is also the term for the graduated markings found on the traditional magnetic compass. Today, a form of compass rose is found on, or featured in, almost all navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, global-positioning systems (GPS), and similar equipment. Types Linguistic anthropological studies have shown that most human communities have four points of cardinal direction. The names given to these directions are usually derived from either locally-specific geographic features (e.g. "towards the hills", "towards the sea") or from celestial bodies (especially the sun) or from atmospheric features (winds, temperature). Most mobile populatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass Rose En 08p
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearings which are commonly stated in degrees. If local variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty (since c. 206 BC),Li Shu-hua, p. 176 and later adopted for navigation by the Song Dynasty Chinese during the 11th centur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auseklis
Auseklis is a Latvian god, a stellar deityLurker, Manfred (2004). ''The Routledge dictionary of gods and goddesses, devils and demons''. Routledge. p. 25. . that represents a celestial body, but possibly not the same as Venus (Rīta zvaigzne) - the first "star" (how Latvians call it) to appear in the mornings on the east side of the sky. He is the third most popular deity in Latvian mythology after Saulė and Mēness, but is almost exclusively mentioned in folk songs. Name The name ''Auseklis'' stems from the root '' aus-'' ('dawn'), attached to the derivative suffix ''-eklis'', and is etymologically related to other Indo-European deities of the dawn. This deity is also variously known as ''Auseklenis'', ''Auseklenč'', ''Ausekleņš'', ''Auseklīts'', ''Auseklītis'', ''Ausekliņis'', ''Ausekliņš'', ''Auseklius''. Role Auseklis is closely associated with Mēness ("moon"). They both are '' Dieva dēli'' ("sons of God"), as is Ūsiņš, and are thus confused with eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Guñelve
A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make them appear as fixed points of light. The most prominent stars have been categorised into constellations and asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye, all within the Milky Way galaxy. A star's life begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Its total mass is the main factor determining its evolution and eventual fate. A star shines for most of its act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kölner Rudergesellschaft 1891
The Kölner Rudergesellschaft 1891 (abbr. ''Kölner RG 1891'' or just KRG, transl. ''Cologne Rowing Association'' or often ''Koelner RG 1891'' in English media) is a rowing club from the German city of Cologne. Overview It is the second oldest rowing organisation in the Cologne Bay Area and has won 14 medals in the German rowing championships. The club was founded in 1891 by craftsmen from the former working class. In 1898 the club joined the German Rowing Association, and in 1913 it was one of the founding members of the Cologne Regatta Association. It was the first German rowing organisation to allow full membership for non-academic athletes. Overall, the club experienced its most successful racing years in the economic boom of the Golden Twenties celebrating German championships in 1926 and 1927 in various boat categories. Again in 1954, the club reached the first place at the German championships in a coxed four boat. The women's squad of the club celebrated its greatest succe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
