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
Physical sciences and engineering Centrifugal force – Type of inertial force Centripetal force – Force directed to the center of rotation Circle of confusion – Blurry region in optics Circle of forces – Diagram of tire forces in vehicle dynamics Circular dichroism – Dichroism with circularly polarized light Circular orbit – Orbit with a fixed distance from the barycenter Mohr's circle – Geometric civil engineering calculation technique Non-uniform circular motion – Object movement along a circular pathPages displaying short descriptions of redirect targets Thomson problem – Arrangement of points on a sphere Uniform circular motion – Object movement along a circular pathPages displaying short descriptions of redirect targets
Geography
Circle of latitude – Geographic notion List of circles of latitude Polar circle – Circle of latitude Arctic Circle – Boundary of the Arctic Antarctic Circle – Boundary of the Antarctic Equator – Imaginary line halfway between Earth's North and South poles Tropic of Cancer – Line of northernmost latitude at which the Sun can be directly overhead Tropic of Capricorn – Line of southernmost latitude at which the Sun can be directly overhead Great-circle distance – Shortest distance between two points on the surface of a sphere Position circle
Artifacts
Addendum circle Belt problem – Mathematics problem Center pivot irrigation – Method of crop irrigationPages displaying short descriptions of redirect targets Circular ditches – Neolithic earthworksPages displaying short descriptions of redirect targets Circular slide rule – Mechanical analog computerPages displaying short descriptions of redirect targets Compass (drafting) – Drafting instrumentPages displaying short descriptions of redirect targets Crop circle – Pattern in a crop field Dip circle – Instrument used for surveying, prospecting and demonstrating geomagnetism List of gear nomenclature Peaucellier–Lipkin linkage – Mechanical linkage transforming rotary motion into linear Pitch circle Repeating circle – Type of angular measurement instrument Timber circle – Rings of upright wooden posts Traffic circle – Traffic intersectionPages displaying short descriptions of redirect targets Setting circles – Astronomy device for a telescope Stone circle – Ring of standing stones Wheel
Glyphs and symbols Borromean rings – Three linked but pairwise separated rings Circled dot (disambiguation) – Graphic and typographic symbolPages displaying short descriptions of redirect targets Circles in Polish mythology Crescent – Symbol of a lunar phase Dotted circle – Non-significant typographic character Ensō – Japanese motif Magic circle – Protective device in ritual magic Olympic emblem – Symbols of the Olympic Games Ouroboros – Symbolic serpent with its tail in its mouth Petosiris to Nechepso – Hellenistic astrologers Quatrefoil – Artistic representation of four circular leaf shapes used in architecture Ring (diacritic) – Diacritic sign Roundel – Circular disc used as a symbol Sacred Chao – Belief system based around the Greek goddess ErisPages displaying short descriptions of redirect targets Shield of the Trinity – Visual symbol expressing the Christian Trinity Solar symbols Squared-circle postmark – Postal marking Sun cross – Circle containing four or more spokes Symbol of Tanit – Goddess of Carthage Trefoil – Artistic representation of three circular leaf shapes used in architecture Triquetra – Triangular motif formed of three interlaced arcs or loops Vesica piscis – Shape that is the intersection of two circles with the same radius Triple Goddess symbol – Triunity of deities in Neopaganism Yin and yang
See also List of specially named circles – Simple curve of Euclidean geometryPages displaying short descriptions of redirect targets Circle (disambiguation) Circle symbol Wandering in circles