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
- Annulus (mathematics)
- Apollonian circles
- Apollonian gasket
- Arbelos
- Archimedean circle
- Archimedes' circles – the twin circles doubtfully attributed to Archimedes
- Archimedes' quadruplets
- Area of a disk
- Bankoff circle
- Thomas Baxter (mathematician)
- Belt problem
- Benz plane
- Bertrand's paradox (probability)
- Bicentric polygon
- Bicentric quadrilateral
- Bipolar coordinates
- Bonnesen's inequality
- Borromean rings
- Brahmagupta's formula
- Brocard circle
- Buffon's needle
- Bundle theorem
- Butterfly theorem
- Carlyle circle
- Carnot's theorem
- Casey's theorem
- Centered trochoid
- Circle
- Central angle
- Circle bundle
- Circle criterion
- Circle graph
- Circle group
- Circle map
- Circle packing
- Circle packing in a circle
- Circle packing in an equilateral triangle
- Circle packing in an isosceles right triangle
- Circle packing theorem
- Circles of Apollonius
- Circle of antisimilitude
- Circular algebraic curve
- Circular distribution
- Circular sector
- Circular segment
- Circular statistics
- Circular surface
- Circumference
- Circumscribed circle (Circumcircle)
- Clifford's circle theorems
- Coaxal circles
- Compass and straightedge
- Concentric
- Concyclic
- Coxeter's loxodromic sequence of tangent circles
- Cyclic quadrilateral
- Cycloid
- Degree (angle)
- Descartes' theorem
- Diameter
- Dinostratus' theorem
- Director circle
- Disk (mathematics)
- Dividing a circle into areas
- Epitrochoid
- Equal incircles theorem
- Ex-tangential quadrilateral
- Fermat–Apollonius circle
- Five circles theorem
- Ford circle
- Fuhrmann circle
- Gauss circle problem
- Geometrography
- Generalised circle
- Gershgorin circle theorem
- GEOS circle
- Great circle
- Hadamard three-circle theorem
- Hardy–Littlewood circle method
- Hawaiian earring
- Homothetic center
- Horn angle
- Horocycle
- Hypotrochoid
- Incircle and excircles of a triangle
- Inscribed angle
- Inscribed angle theorem
- Inscribed circle
- Inversive distance
- Inversive geometry
- Irrational rotation
- Isodynamic point
- Isoperimetric problem
- Japanese theorem for cyclic polygons
- Japanese theorem for cyclic quadrilaterals
- Johnson circles
- Kosnita's theorem
- Lazy caterer's sequence
- Lemoine line
- Lester's theorem
- Limiting cases of Apollonius' problem
- List of topics related to pi
- Lune
- Lune of Hippocrates
- Magic circle (mathematics)
- Malfatti circles
- Measurement of a Circle
- Midpoint-stretching polygon
- Milne-Thomson circle theorem
- Miquel's theorem
- Monge's theorem
- Mean of circular quantities
- Mrs. Miniver's problem
- Nine-point circle
- Orthocentroidal circle
- Osculating circle
- Overlapping circles grid
- Pappus chain
- Peaucellier–Lipkin linkage
- Pi
- Pivot theorem
- Pizza theorem
- Polar circle (geometry)
- Pole and polar
- Polygon-circle graph
- Poncelet's porism
- Power center (geometry)
- Power of a point
- Problem of Apollonius
- Proof that pi is irrational
- Ptolemy's theorem
- Ptolemy's table of chords
- Quasicircle
- Radical axis
- Radius
- Regiomontanus' angle maximization problem
- Riemannian circle
- Robbins pentagon
- Salinon
- Schinzel circle
- Schoch line
- Schoch circles
- Semicircle
- Seven circles theorem
- Six circles theorem
- Smallest circle problem
- Spieker circle
- Splitting circle
- Squaring the circle
- Squircle
- Steiner chain
- Tammes problem
- Tangent lines to circles
- Tangent circles
- Tangential polygon
- Tangential quadrilateral
- Tarski's circle-squaring problem
- Thales' theorem
- Twin circles
- Unit circle
- Van Lamoen circle
- Versor
- Villarceau circles
- von Mises distribution
- Wigner semicircle distribution
- Woo circles
- Wrapped distribution
Physics
- Centrifugal force
- Centripetal force
- Circle of confusion
- Circular dichroism
- Circular orbit
- Mohr's circle
- Non-uniform circular motion
- Thomson problem
- Uniform circular motion
Geography
- Arctic Circle
- Antarctic Circle
- Circle of latitude
- Equator
- Great-circle distance
- Polar circle
- Position circle
- Tropic of Cancer
- Tropic of Capricorn
Artifacts
- Addendum circle
- Belt problem
- Circular ditches
- Circular slide rule
- Compass (drafting)
- Crop circle
- Dip circle
- List of gear nomenclature
- Peaucellier–Lipkin linkage
- Pitch circle
- Repeating circle
- Timber circle
- Traffic circle
- Setting circles
- Stone circle
- Wheel
Glyphs and symbols
- Borromean rings
- Circled dot
- Circles in Polish mythology
- Crescent
- Dotted circle
- Enso
- Magic circle
- Olympic emblem
- Ouroboros
- Petosiris to Nechepso
- Quatrefoil
- Ring (diacritic)
- Roundel
- Sacred Chao
- Shield of the Trinity
- Solar symbols
- Squared-circle postmark
- Sun cross
- Symbol of Tanit
- Trefoil
- Triquetra
- Vesica piscis
- Triple Goddess symbol
- Yin and yang