thumb|right|Four cyclic polygons, each with a circle circumscribed about it
In geometry, a '''circumscribed circle''' for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle.
* Circumcircle, the circumscribed circle of a triangle, which always exists for a given triangle.<ref>{{cite book |last1=Isaacs |first1=I. Martin |author1-link=I. Martin Isaacs |title=Geometry for college students |date=2009 |publisher=American Mathematical Society |isbn=978-0-8218-4794-7 |page=50 |url=https://books.google.com/books?id=0ahK8UneO3kC&q=circumcircle&pg=PA50}}</ref> * Cyclic polygon, a general polygon that can be circumscribed by a circle. The vertices of this polygon are concyclic points. All triangles are cyclic polygons. * Cyclic quadrilateral, a special case of a cyclic polygon.
== See also == * Smallest-circle problem, the related problem of finding the circle with minimal radius containing an arbitrary set of points, not necessarily passing through them. * Inscribed figure
== References == {{Reflist}}
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