The closed ball with center and radius is defined by
Closed Ball
See also
Ball, Closed Disk, Open BallExplore with Wolfram|Alpha
References
Croft, H. T.; Falconer, K. J.; and Guy, R. K. Unsolved Problems in Geometry. New York: Springer-Verlag, p. 1, 1991.Referenced on Wolfram|Alpha
Closed BallCite this as:
Weisstein, Eric W. "Closed Ball." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ClosedBall.html