Category:三角形と円に関する定理

Musselman's theorem

Van Schooten's theorem

Lexell's theorem

Cramer–Castillon problem

Van Lamoen circle

Simson line

Six circles theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Fuhrmann circle

Kosnita's theorem

Pompeiu's theorem

Lester's theorem

Harcourt's theorem

Reuschle's theorem

Miquel's theorem

Griffiths' theorem

Conway circle theorem

Thébault's theorem

Lune of Hippocrates

Thales's theorem

Incenter–excenter lemma

Feuerbach's theorem

Japanese theorem for cyclic polygons