Category:三角形と円に関する定理

Japanese theorem for cyclic polygons

Musselman's theorem

Lune of Hippocrates

Simson line

Fuhrmann circle

Thébault's theorem

Cramer–Castillon problem

Van Lamoen circle

Pompeiu's theorem

Incenter–excenter lemma

Harcourt's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Six circles theorem

Kosnita's theorem

Reuschle's theorem

Lester's theorem

Griffiths' theorem

Conway circle theorem

Miquel's theorem

Van Schooten's theorem

Thales's theorem