"A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre; equivalently it ...
[Read more]
is the curve traced out by a point that moves in a plane so that its distance from a given point is constant. The distance between any point of the circle and the centre is called the radius. Usually, the radius is required to be a positive number (Circle with
r
=
0
{\displaystyle r=0}
is a degenerated case). This article is about circles in Euclidean geometry, and, in particular, the Euclidean plane, except where otherwise noted." - (en.wikipedia.org 14.12.2021)
