It is called the hub.
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
A part of a circle is an arc.it's called an ARC.