Category:三角形と円に関する定理

Japanese theorem for cyclic polygons

Thales's theorem

Incenter–excenter lemma

Lune of Hippocrates

Thébault's theorem

Fuhrmann circle

Pompeiu's theorem

Miquel's theorem

Harcourt's theorem

Euler's theorem in geometry

Carnot's theorem (inradius, circumradius)

Polar circle (geometry)

Griffiths' theorem

Kosnita's theorem

Van Lamoen circle

Van Schooten's theorem

Reuschle's theorem

Cramer–Castillon problem

Simson line

Lester's theorem

Six circles theorem

Musselman's theorem

Conway circle theorem

Feuerbach point