Category:三角形と円に関する定理

Thales's theorem

Japanese theorem for cyclic polygons

Musselman's theorem

Miquel's theorem

Van Schooten's theorem

Simson line

Incenter–excenter lemma

Cramer–Castillon problem

Van Lamoen circle

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

Pompeiu's theorem

Harcourt's theorem

Lester's theorem

Lexell's theorem

Feuerbach's theorem

Lune of Hippocrates

Griffiths' theorem

Conway circle theorem