Sphere
The points are all the same distance from the center of the circle. The distance between the center and any point is the radius of the circle.
A circle.
The set of all points a given distance from a center point is a circle. The given distance is the radius, and the given point is the center. Or, in 3 dimensional space, a sphere.
A sphere
A circle or a sphere
A circle
Sphere
It is a sphere
Sphere
circle
A solid sphere perhaps?
The points are all the same distance from the center of the circle. The distance between the center and any point is the radius of the circle.
It is the circle's center point
A circle.
A circle or sphere.
The center