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Undecagon
In geometry, a hendecagon (also undecagon or endecagon) or 11-gon is an eleven-sided polygon. (The name ''hendecagon'', from Greek ''hendeka'' "eleven" and ''–gon'' "corner", is often preferred to the hybrid ''undecagon'', whose first part is formed from Latin ''undecim'' "eleven".) Regular hendecagon A '' regular hendecagon'' is represented by Schläfli symbol . A regular hendecagon has internal angles of 147. degrees (=147 \tfrac degrees). The area of a regular hendecagon with side length ''a'' is given by. :A = \fraca^2 \cot \frac \simeq 9.36564\,a^2. As 11 is not a Fermat prime, the regular hendecagon is not constructible with compass and straightedge. Because 11 is not a Pierpont prime, construction of a regular hendecagon is still impossible even with the usage of an angle trisector. Close approximations to the regular hendecagon can be constructed. For instance, the ancient Greek mathematicians approximated the side length of a hendecagon inscribed in a unit circl ... [...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 geometries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihedral Symmetry
In mathematics, a dihedral group is the group of symmetries of a regular polygon, which includes rotations and reflections. Dihedral groups are among the simplest examples of finite groups, and they play an important role in group theory, geometry, and chemistry. The notation for the dihedral group differs in geometry and abstract algebra. In geometry, or refers to the symmetries of the -gon, a group of order . In abstract algebra, refers to this same dihedral group. This article uses the geometric convention, . Definition Elements A regular polygon with n sides has 2n different symmetries: n rotational symmetries and n reflection symmetries. Usually, we take n \ge 3 here. The associated rotations and reflections make up the dihedral group \mathrm_n. If n is odd, each axis of symmetry connects the midpoint of one side to the opposite vertex. If n is even, there are n/2 axes of symmetry connecting the midpoints of opposite sides and n/2 axes of symmetry connecting oppo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regular Star Polygon 11-2
The term regular can mean normal or in accordance with rules. It may refer to: People * Moses Regular (born 1971), America football player Arts, entertainment, and media Music * "Regular" (Badfinger song) * Regular tunings of stringed instruments, tunings with equal intervals between the paired notes of successive open strings Other uses in arts, entertainment, and media * Regular character, a main character who appears more frequently and/or prominently than a recurring character * Regular division of the plane, a series of drawings by the Dutch artist M. C. Escher which began in 1936 * ''Regular Show'', an animated television sitcom * '' The Regular Guys'', a radio morning show Language * Regular inflection, the formation of derived forms such as plurals in ways that are typical for the language ** Regular verb * Regular script, the newest of the Chinese script styles Mathematics There are an extremely large number of unrelated notions of "regularity" in mathematics. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hendecagram
In geometry, a hendecagram (also endecagram or endekagram) is a star polygon that has eleven vertices. The name ''hendecagram'' combines a Greek numeral prefix, '' hendeca-'', with the Greek suffix ''-gram''. The ''hendeca-'' prefix derives from Greek ἕνδεκα (ἕν + δέκα, one + ten) meaning " eleven". The ''-gram'' suffix derives from γραμμῆς (''grammēs'') meaning a line. Regular hendecagrams There are four regular hendecagrams, which can be described by the notation , , , and ; in this notation, the number after the slash indicates the number of steps between pairs of points that are connected by edges. These same four forms can also be considered as stellations of a regular hendecagon. Since 11 is prime, all hendecagrams are star polygons and not compound figures. Construction As with all odd regular polygons and star polygons whose orders are not products of distinct Fermat primes, the regular hendecagrams cannot be constructed with compass and straigh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Susan B
Susan is a feminine given name, from Persian "Susan" (lily flower), from Egyptian '' sšn'' and Coptic ''shoshen'' meaning "lotus flower", from Hebrew ''Shoshana'' meaning "lily" (in modern Hebrew this also means "rose" and a flower in general), from Greek ''Sousanna'', from Latin ''Susanna'', from Old French ''Susanne''. Variations * Susana (given name), Susanna, Susannah * Suzana, Suzanna, Suzannah * Susann, Suzan, Suzann * Susanne (given name), Suzanne * Susanne (given name) * Suzan (given name) * Suzanne * Suzette (given name) * Suzy (given name) * Zuzanna (given name) *Cezanne (Avant-garde) Nicknames Common nicknames for Susan include: * Sue, Susie, Susi (German), Suzi, Suzy, Suzie, Suze, Poosan, Sanna, Suzie, Sookie, Sukie, Sukey, Subo, Suus (Dutch), Shanti In other languages * fa, سوسن (Sousan, Susan) ** tg, Савсан (Savsan), tg, Сӯсан (Sūsan) * ku, Sosna,Swesne * ar, سوسن (Sawsan) * hy, Շուշան (Šušan) * (Sushan) * S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reuleaux Hendecagon
A Reuleaux triangle is a curved triangle with constant width, the simplest and best known curve of constant width other than the circle. It is formed from the intersection of three circular disks, each having its center on the boundary of the other two. Constant width means that the separation of every two parallel supporting lines is the same, independent of their orientation. Because its width is constant, the Reuleaux triangle is one answer to the question "Other than a circle, what shape can a manhole cover be made so that it cannot fall down through the hole?" Reuleaux triangles have also been called spherical triangles, but that term more properly refers to triangles on the curved surface of a sphere. They are named after Franz Reuleaux,. a 19th-century German engineer who pioneered the study of machines for translating one type of motion into another, and who used Reuleaux triangles in his designs. However, these shapes were known before his time, for instance by the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Rupee
The Indian rupee ( symbol: ₹; code: INR) is the official currency in the republic of India. The rupee is subdivided into 100 ''paise'' (singular: ''paisa''), though as of 2022, coins of denomination of 1 rupee are the lowest value in use whereas 2000 rupees is the highest. The issuance of the currency is controlled by the Reserve Bank of India. The Reserve Bank manages currency in India and derives its role in currency management on the basis of the Reserve Bank of India Act, 1934. Etymology The immediate precursor of the rupee is the ''rūpiya''—the silver coin weighing 178 grains minted in northern India by first Sher Shah Suri during his brief rule between 1540 and 1545 and adopted and standardized later by the Mughal Empire. The weight remained unchanged well beyond the end of the Mughals until the 20th century. Though Pāṇini mentions (), it is unclear whether he was referring to coinage. ''Arthashastra'', written by Chanakya, prime minister to the first Maurya ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hendecagonal Prism
In geometry, the hendecagonal prism is one in an infinite set of convex prisms formed by square sides and two regular polygon caps, in this case two hendecagon In geometry, a hendecagon (also undecagon or endecagon) or 11-gon is an eleven-sided polygon. (The name ''hendecagon'', from Greek ''hendeka'' "eleven" and ''–gon'' "corner", is often preferred to the hybrid ''undecagon'', whose first part is f ...s. So, it has 2 hendecagons and 11 squares as its faces. Related polyhedra External links * Prismatoid polyhedra {{Polyhedron-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loonie
The loonie (french: huard), formally the Canadian one-dollar coin, is a gold-coloured Canadian coin that was introduced in 1987 and is produced by the Royal Canadian Mint at its facility in Winnipeg. The most prevalent versions of the coin show a common loon, a bird found throughout Canada, on the reverse and Queen Elizabeth II, the nation's head of state at the time of the coin's issue, on the obverse. Various commemorative and specimen-set editions of the coin with special designs replacing the loon on the reverse have been minted over the years. The coin's outline is an 11-sided Reuleaux polygon. Its diameter of 26.5 mm and its 11-sidedness matched that of the already-circulating Susan B. Anthony dollar in the United States, and its thickness of 1.95 mm was a close match to the latter's 2.0 mm. Its gold colour differed from the silver-coloured Anthony dollar; however, the succeeding Sacagawea and Presidential dollars matched the loonie's overall hue. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Dollar
The Canadian dollar ( symbol: $; code: CAD; french: dollar canadien) is the currency of Canada. It is abbreviated with the dollar sign $, there is no standard disambiguating form, but the abbreviation Can$ is often suggested by notable style guides for distinction from other dollar-denominated currencies. It is divided into 100 cents (¢). Owing to the image of a common loon on its reverse, the dollar coin, and sometimes the unit of currency itself, are sometimes referred to as the ''loonie'' by English-speaking Canadians and foreign exchange traders and analysts. Accounting for approximately 2% of all global reserves, the Canadian dollar is the fifth-most held reserve currency in the world, behind the U.S. dollar, the euro, the yen and sterling. The Canadian dollar is popular with central banks because of Canada's relative economic soundness, the Canadian government's strong sovereign position, and the stability of the country's legal and political systems. Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directed Edge
In mathematics, and more specifically in graph theory, a directed graph (or digraph) is a graph that is made up of a set of vertices connected by directed edges, often called arcs. Definition In formal terms, a directed graph is an ordered pair where * ''V'' is a set whose elements are called '' vertices'', ''nodes'', or ''points''; * ''A'' is a set of ordered pairs of vertices, called ''arcs'', ''directed edges'' (sometimes simply ''edges'' with the corresponding set named ''E'' instead of ''A''), ''arrows'', or ''directed lines''. It differs from an ordinary or undirected graph, in that the latter is defined in terms of unordered pairs of vertices, which are usually called ''edges'', ''links'' or ''lines''. The aforementioned definition does not allow a directed graph to have multiple arrows with the same source and target nodes, but some authors consider a broader definition that allows directed graphs to have such multiple arcs (namely, they allow the arc set to be a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaim Goodman-Strauss
Chaim Goodman-Strauss (born June 22, 1967 in Austin TX) is an American mathematician who works in convex geometry, especially aperiodic tiling. He is on the faculty of the University of Arkansas and is a co-author with John H. Conway of ''The Symmetries of Things'', a comprehensive book surveying the mathematical theory of patterns. Education and career Goodman-Strauss received both his B.S. (1988) and Ph.D. (1994) in mathematics from the University of Texas at Austin.Chaim Goodman-Strauss The College Board His doctoral advisor was . He joined the faculty at the |
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