torussen

A torus is a surface of revolution generated by revolving a closed curve, most commonly a circle, in three-dimensional space about an axis coplanar with the curve. The shape resembles a donut or an inner tube. The term "torus" can also refer to the solid object bounded by such a surface. The most common type of torus is the ring torus, which is formed by rotating a circle around an axis that does not intersect the circle.

The shape of a torus is defined by two radii: the major radius, which is the distance from the center of the hole to the center of the tube, and the minor radius, which is the radius of the tube itself. If the minor radius is zero, the torus degenerates into a circle. If the minor radius is equal to the major radius, the torus is called a horn torus. If the minor radius is larger than the major radius, the torus is called a spindle torus, where the hole closes up.

In mathematics, tori are important examples of surfaces with genus one. They appear in various fields, including topology, geometry, and physics. For instance, in physics, a toroidal magnetic field is a magnetic field whose field lines are all closed curves within a torus. The concept of a torus is also used in computer graphics and animation to model objects with a hole.