Category:三角形と円に関する定理

Thales's theorem

Musselman's theorem

Japanese theorem for cyclic polygons

Feuerbach's theorem

Simson line

Cramer–Castillon problem

Lune of Hippocrates

Pompeiu's theorem

Van Lamoen circle

Incenter–excenter lemma

Van Schooten's theorem

Six circles theorem

Thébault's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Reuschle's theorem

Fuhrmann circle

Kosnita's theorem

Harcourt's theorem

Lester's theorem

Lexell's theorem

Griffiths' theorem

Miquel's theorem

Conway circle theorem