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List Of Circle Topics
This list of circle topics includes things related to the geometric shape, either abstractly, as in idealizations studied by geometers, or concretely in physical space. It does not include metaphors like "inner circle" or "circular reasoning" in which the word does not refer literally to the geometric shape. Geometry and other areas of mathematics * Circle ; Circle anatomy * Annulus (mathematics) * Area of a disk * Bipolar coordinates * Central angle * Circular sector * Circular segment * Circumference * Concentric * Concyclic * Degree (angle) * Diameter * Disk (mathematics) * Horn angle * ''Measurement of a Circle'' * ** List of topics related to * Pole and polar * Power of a point * Radical axis * Radius ** Radius of convergence ** Radius of curvature * Sphere * Tangent lines to circles * Versor ; Specific circles * Apollonian circles * Circles of Apollonius * Archimedean circle * Archimedes' circles – the twin circles doubtfully attributed to Archimedes * Archimed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ford Circles
In mathematics, a Ford circle is a circle with center at (p/q,1/(2q^2)) and radius 1/(2q^2), where p/q is an irreducible fraction, i.e. p and q are coprime integers. Each Ford circle is tangent to the horizontal axis y=0, and any two Ford circles are either tangent or disjoint from each other. History Ford circles are a special case of mutually tangent circles; the base line can be thought of as a circle with infinite radius. Systems of mutually tangent circles were studied by Apollonius of Perga, after whom the problem of Apollonius and the Apollonian gasket are named.. In the 17th century René Descartes discovered Descartes' theorem, a relationship between the reciprocals of the radii of mutually tangent circles. Ford circles also appear in the Sangaku (geometrical puzzles) of Japanese mathematics. A typical problem, which is presented on an 1824 tablet in the Gunma Prefecture, covers the relationship of three touching circles with a common tangent. Given the size of the tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
