Category:三角形に関する定理

Exterior angle theorem

Midpoint theorem (triangle)

Morley's trisector theorem

Apollonius's theorem

Bottema's theorem

L'Huilier's theorem

Napoleon'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)

Feuerbach hyperbola

Angle bisector theorem

Law of cotangents

Ceva's theorem

Menelaus's theorem

Law of tangents

Desargues's theorem

Stewart's theorem

Routh's theorem

Law of sines

Law of cosines

Heron's formula