Editing Triangle (section)

=== Rigidity ===
{{main article|Structural rigidity}}
[[File:Structural rigidity basic examples.svg|thumb|Rigidity of a triangle and square]]
Unlike a rectangle, which may collapse into a [[parallelogram]] from pressure to one of its points,{{sfn|Jordan|Smith|2010|p=[https://books.google.com/books?id=tevqDwAAQBAJ&pg=PA834 834]}} triangles are sturdy because specifying the lengths of all three sides determines the angles.{{sfn|Gonick|2024|p=125}} Therefore, a triangle will not change shape unless its sides are bent or extended or broken or if its joints break; in essence, each of the three sides supports the other two. A rectangle, in contrast, is more dependent on the strength of its joints in a structural sense.

Triangles are strong in terms of rigidity, but while packed in a [[tessellation|tessellating]] arrangement triangles are not as strong as [[hexagon]]s under compression (hence the prevalence of hexagonal forms in [[nature]]). Tessellated triangles still maintain superior strength for [[cantilever]]ing, however, which is why engineering makes use of [[space frame|tetrahedral trusses]].{{cn|date=August 2024}}