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| ==Etymology== | | ==Etymology== |
| [[Latin]], [[ray]], radius | | [[Latin]], [[ray]], radius |
− | *Date: circa [http://www.wikipedia.org/wiki/17th_Century 1611] | + | *Date: circa [https://www.wikipedia.org/wiki/17th_Century 1611] |
| ==Definitions== | | ==Definitions== |
| *1 : a line segment extending from the [[center]] of a [[circle]] or [[sphere]] to the [[circumference]] or bounding [[surface]] | | *1 : a line segment extending from the [[center]] of a [[circle]] or [[sphere]] to the [[circumference]] or bounding [[surface]] |
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| The inradius of a [[geometric]] figure is usually the radius of the largest [[circle]] or [[sphere]] contained in it. The inner radius of a ring, tube or other hollow object is the radius of its cavity. | | The inradius of a [[geometric]] figure is usually the radius of the largest [[circle]] or [[sphere]] contained in it. The inner radius of a ring, tube or other hollow object is the radius of its cavity. |
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− | The radius of a regular polygon (or polyhedron) is the distance from its [[center]] to any of its [[vertices]]; which is also its circumradius. The inradius of a regular polygon is also called [http://en.wikipedia.org/wiki/Apothem apothem]. | + | The radius of a regular polygon (or polyhedron) is the distance from its [[center]] to any of its [[vertices]]; which is also its circumradius. The inradius of a regular polygon is also called [https://en.wikipedia.org/wiki/Apothem apothem]. |
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− | In [http://en.wikipedia.org/wiki/Graph_theory graph theory], the radius of a graph is the minimum over all [[vertices]] u of the maximum distance from u to any other [[vertex]] of the graph. | + | In [https://en.wikipedia.org/wiki/Graph_theory graph theory], the radius of a graph is the minimum over all [[vertices]] u of the maximum distance from u to any other [[vertex]] of the graph. |
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− | The [[name]] comes from [[Latin]] radius, meaning "ray" but also the spoke of a chariot [[wheel]]. The plural in [[English]] is radii (as in [[Latin]]), but radiuses can be used, though it rarely is.[http://en.wikipedia.org/wiki/Radius] | + | The [[name]] comes from [[Latin]] radius, meaning "ray" but also the spoke of a chariot [[wheel]]. The plural in [[English]] is radii (as in [[Latin]]), but radiuses can be used, though it rarely is.[https://en.wikipedia.org/wiki/Radius] |
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| [[Category: Mathematics]] | | [[Category: Mathematics]] |