It is called the hub.
hubHub
It's called a hub.
It's called a hub.
The center part of the wheel is a spin
the wheel The part that turns people in a circle.
The line from the center of a circle to a point on the circle is the radius.
A central angle.The section of the circle formed by that angle and the part of the circle (the part being the circumference) between the radii is called a sector.
The line from the center of a circle to a point on the circle is the radius.
A great circle is any circle on the surface of a sphere whose center is at the center of the sphere. The shortest distance between two points on the surface of a sphere is a part of the great circle that passes through them.
radius
if you mean the point that starts at the edge of the circle and ends in the center then this is the radius (: