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
Pi
List of topics related to pi
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
Archimedes' quadruplets
Circle of antisimilitude
Bankoff circle
Brocard circle
Carlyle circle
Circumscribed circle (circumcircle)

Midpoint-stretching polygon

Coaxal circles
Director circle
Fermat–Apollonius circle
Ford circle
Fuhrmann circle
Generalised circle
GEOS circle
Great circle
Great-circle distance
Circle of a sphere
Horocycle
Incircle and excircles of a triangle
Inscribed circle
Johnson circles
Magic circle (mathematics)
Malfatti circles
Nine-point circle
Orthocentroidal circle
Osculating circle
Riemannian circle
Schinzel circle
Schoch circles
Spieker circle
Tangent circles
Twin circles
Unit circle
Van Lamoen circle
Villarceau circles
Woo circles

Circle-derived entities

Apollonian gasket
Arbelos
Bicentric polygon
Bicentric quadrilateral
Coxeter's loxodromic sequence of tangent circles
Cyclic quadrilateral
Cycloid
Ex-tangential quadrilateral
Hawaiian earring
Inscribed angle
Inscribed angle theorem
Inversive distance
Inversive geometry
Irrational rotation
Lens (geometry)
Lune
Lune of Hippocrates
Lazy caterer's sequence
Overlapping circles grid
Pappus chain
Polar circle (geometry)
Power center (geometry)
Salinon
Semicircle
Squircle
Steiner chain
Tangential polygon
Tangential quadrilateral

Roulettes

Centered trochoid
Epitrochoid

Epicycloid
Cardioid
Nephroid
Deferent and epicycle

Hypotrochoid

Hypocycloid
Astroid
Deltoid curve

Topology

Borromean rings
Circle bundle
Quasicircle

Circle-related theory

Apollonius' problem
Limiting cases of Apollonius' problem
Belt problem
Benz plane
Bertrand's paradox (probability)
Bonnesen's inequality
Brahmagupta's formula
Buffon's needle problem
Bundle theorem
Butterfly theorem
Carnot's theorem
Casey's theorem
Circle graph
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
Introduction to Circle Packing – a book by Kenneth Stephenson
Circular surface
Clifford's circle theorems
Compass and straightedge
Mohr–Mascheroni theorem
Poncelet–Steiner theorem
Descartes' theorem
Dinostratus' theorem
Dividing a circle into areas
Equal incircles theorem
Five circles theorem
Gauss circle problem
Gershgorin circle theorem
Geometrography
Hadamard three-circle theorem
Hardy–Littlewood circle method
Isoperimetric problem
Japanese theorem for cyclic polygons
Japanese theorem for cyclic quadrilaterals
Kosnita's theorem
Lester's theorem
Milne-Thomson circle theorem
Miquel's theorem
Monge's theorem
Mrs. Miniver's problem
Pivot theorem
Pizza theorem
Squaring the circle
Poncelet's porism
Ptolemy's theorem
Ptolemy's table of chords
Regiomontanus' angle maximization problem
Ring lemma
Seven circles theorem
Six circles theorem
Smallest circle problem
Tammes problem
Tarski's circle-squaring problem
Thales' theorem

Circle tangents in non-geometric theory

Circle criterion
Circle group
Group of rational points on the unit circle
Circular algebraic curve
Circular distribution
Circular statistics
Mean of circular quantities
Polygon-circle graph
Splitting circle method
von Mises distribution
Wigner semicircle distribution
Wrapped distribution
Wrapped Cauchy distribution
Wrapped normal distribution