A sphere has one point of symmetry (at its very center) if one considers rotational symmetry in its three dimensions. If one is only considering reflectional symmetry, it would have an infinite number of lines of symmetry.
To describe a shape's rotational symmetries, you would write the angle. For example, let's use a square. If you rotate a square 90 degrees, it will look exactly the same, and 180 will be the same too, so a square's rotational symmetries are 90 and 180 degrees.
A sphere is as symetrical as any shape can get. It has an infinite amount of lines of symetry if that line goes through the center
There are various characteristics and attributes that would describe a sphere. A sphere is a perfectly symmetrically round or circular three dimensional object.
By saying: It is a red sphere.
a sphere or 3D circle
A sphere would fit the given description
A circle or a sphere would seem to fit the given conditions
Yes. For example, the center of mass of a hollow sphere would be at the empty center of that sphere.
Technically you can not trace a sphere. If the base conditions are the same as for the other solid shapes, for example a cylinder, there is a base on which the cylinder rests, which creates the circle when it is traced. A sphere on a base would be touching in one point, which would be a dot. If you trace half a sphere, yes, than you do get a circle.
the gradient of a graph at any point.
It's the middle point of line. Hardly! How far would that be from a point 3/4 way along the line? Try centre of a circle, or of a sphere.
The focal point is in front of the retina