Category:三角形と円に関する定理

Japanese theorem for cyclic polygons

Miquel's theorem

Musselman's theorem

Van Schooten's theorem

Cramer–Castillon problem

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

Lune of Hippocrates

Fuhrmann circle

Kosnita's theorem

Feuerbach's theorem

Harcourt's theorem

Lester's theorem

Lexell's theorem

Griffiths' theorem

Simson line

Conway circle theorem

Thales's theorem