Explore Torus on MathWorld

A torus is a closed surface containing a single hole that is shaped like a doughnut.

Torus is a college-level concept that would be first encountered in a topology course.


Surface: A surface is a two-dimensional piece of three-dimensional space.

Classroom Articles on Topology (Up to College Level)

  • Closed Set
  • Open Set
  • Dimension
  • Point-Set Topology
  • Homeomorphism
  • Projective Plane
  • Metric
  • Projective Space
  • Metric Space
  • Subspace
  • Möbius Strip
  • Topological Space
  • Neighborhood
  • Topology