Linked from

The 65 pages that link to Triangle, each with the reason it gives.

• Droz-Farny line theoremNarrower topic: Its sides provide the lines intersected by the perpendiculars.

• Equal Incircles TheoremNarrower topic: The theorem concerns pairs of these figures.

• Erdős–Mordell inequalityNarrower topic: The inequality compares distances within this basic geometric figure.

• Hinge theoremNarrower topic: The theorem compares two triangles sharing equal corresponding side lengths.

• Inverse Pythagorean theoremNarrower topic: The converse applies to triangles whose three side lengths are known.

• Japanese theoremNarrower topic: Each region formed by the diagonals is a triangle whose inradius enters the theorem.

• Japanese theorem for cyclic polygonsNarrower topic: Every region in the theorem’s vertex-based triangulation is a triangle.

• Legendre's theorem on spherical trianglesCompared with: It is the target figure, but its angles require correction to approximate a spherical triangle.

• Marden's theoremNarrower topic: The three noncollinear polynomial roots form the triangle that determines the ellipse.

• Mollweide's formulaNarrower topic: Mollweide's formulas apply to the side-angle relationships of this basic figure.

• Monsky's theoremNarrower topic: The pieces in the partition are triangles, measured by their areas.

• Pasch's theoremRelated: Its three sides define the boundary that the entering line must cross again.

• Pompeiu's theoremNarrower topic: Pompeiu's theorem concerns when three measured lengths can be the sides of a triangle.

• Thomsen's theoremRelated: Its vertices and sides organize the sequence of perspectivities.

• Van Lamoen circleNarrower topic: The construction begins with a triangle and depends on its vertices and opposite sides.