Category:三角形と円に関する定理

Thales's theorem

Simson line

Musselman's theorem

Lune of Hippocrates

Feuerbach's theorem

Cramer–Castillon problem

Van Schooten's theorem

Pompeiu's theorem

Van Lamoen circle

Six circles theorem

Incenter–excenter lemma

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

Japanese theorem for cyclic polygons

Lester's theorem

Lexell's theorem

Griffiths' theorem

Conway circle theorem

Miquel's theorem