Category:三角形と円に関する定理

Feuerbach's theorem

Thales's theorem

Musselman's theorem

Cramer–Castillon problem

Incenter–excenter lemma

Pompeiu's theorem

Lune of Hippocrates

Van Lamoen circle

Six circles theorem

Thébault's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Simson line

Reuschle's theorem

Fuhrmann circle

Kosnita's theorem

Miquel's theorem

Japanese theorem for cyclic polygons

Harcourt's theorem

Lester's theorem

Van Schooten's theorem

Lexell's theorem

Griffiths' theorem

Conway circle theorem