Category:三角形と円に関する定理

Lune of Hippocrates

Japanese theorem for cyclic polygons

Van Schooten's theorem

Musselman's theorem

Miquel's theorem

Incenter–excenter lemma

Cramer–Castillon problem

Simson line

Van Lamoen circle

Harcourt's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Thébault's theorem

Fuhrmann circle

Kosnita's theorem

Lester's theorem

Pompeiu's theorem

Reuschle's theorem

Six circles theorem

Conway circle theorem

Griffiths' theorem

Thales's theorem