Triangulation
Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.
One sequence, counting everything
The number of ways to cut a polygon into triangles is 1, 2, 5, 14, 42. So is the number of ways to bracket a product, the number of binary trees, and the number of paths that never cross a diagonal. They are the same count, and the reason is one picture.
The plane, divided by whoever is nearest
Scatter some points and colour every other point of the plane by which one is closest. The result is a tiling nobody designed, and its dual triangulation has a property that no part of the construction mentions.
Named alongside it
The objects these essays reach for when they reach for this one.
ConvexityBijectionBinary treesCatalan numbersCircleDelaunay triangulationDualityEuler characteristicLattice pathsNearest neighbourPerpendicular bisectorPlanar graph