Category:三角形と円に関する定理

Japanese theorem for cyclic polygons

Thales's theorem

Simson line

Musselman's theorem

Fuhrmann circle

Thébault's theorem

Cramer–Castillon problem

Van Lamoen circle

Pompeiu's theorem

Harcourt's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Kosnita's theorem

Incenter–excenter lemma

Lune of Hippocrates

Reuschle's theorem

Lester's theorem

Six circles theorem

Griffiths' theorem

Conway circle theorem

Miquel's theorem

Van Schooten's theorem