Category:三角形と円に関する定理

Thales's theorem

Lune of Hippocrates

Musselman's theorem

Simson line

Fuhrmann circle

Cramer–Castillon problem

Van Lamoen circle

Harcourt's theorem

Pompeiu's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Lexell's theorem

Thébault's theorem

Kosnita's theorem

Miquel's theorem

Reuschle's theorem

Lester's theorem

Incenter–excenter lemma

Six circles theorem

Griffiths' theorem

Conway circle theorem

Japanese theorem for cyclic polygons

Van Schooten's theorem