English

Straight Line motion with rigid sets

Metric Geometry 2014-01-21 v1

Abstract

If one is given a rigid triangle in the plane or space, we show that the only motion possible, where each vertex of the triangle moves along a straight line, is given by a hypocycloid line drawer in the plane, and a natural extension in three-space. Each point lies on a circle which rolls around, without slipping, inside a larger circle of twice its diameter.

Keywords

Cite

@article{arxiv.1401.4743,
  title  = {Straight Line motion with rigid sets},
  author = {Robert Connelly and Luis Montejano},
  journal= {arXiv preprint arXiv:1401.4743},
  year   = {2014}
}
R2 v1 2026-06-22T02:49:23.969Z