Triangle -- from Wolfram MathWorld

Paralogic Triangles -- from Wolfram MathWorld

The Yanghui Triangle, Part I – The Shaw Show

Circumcircle3D Wolfram Function Repository

Orthic Triangle -- from Wolfram MathWorld

Splitter -- from Wolfram MathWorld

The Wolfram MathWorld List of Unsolved Problems

Cevian Triangle -- from Wolfram MathWorld Euclidean geometry, Plane geometry, Learning tools

A standard pyramidal Galton board, from Wolfram MathWorld [28].

File:Schlegeldiagramm des Tetraeders.svg - Wikipedia