Category:三角形に関する定理

Desargues's theorem

Morley's trisector theorem

Stewart's theorem

Feuerbach hyperbola

Napoleon's theorem

L'Huilier's theorem

Bottema's theorem

Pappus's area theorem

Droz-Farny line theorem

Thomsen's theorem

Carnot's theorem (conics)

Carnot's theorem (perpendiculars)

Maxwell's theorem (geometry)

Jacobi's theorem (geometry)

Routh's theorem

Apollonius's theorem

Angle bisector theorem

Law of cotangents

Exterior angle theorem

Law of tangents

Ceva's theorem

Law of sines

Midpoint theorem (triangle)

Menelaus's theorem

Heron's formula

Law of cosines