Source: wikibot/annulus-mathematics
= Annulus (mathematics)
{wiki=Annulus_(mathematics)}
In mathematics, an annulus (plural: annuli) is a ring-shaped object that is formed by the region between two concentric circles. It can be described in the following way: 1. **Definition**: An annulus is the set of points in a plane that are situated between two circles, typically denoted by an inner circle with radius \\( r_1 \\) and an outer circle with radius \\( r_2 \\), where \\( r_2 > r_1 \\).