Parallel lines within a circle are infinite.
Cdm
A circle intersected by a pair of parallel lines.
They do not have any specific name.
If you mean a 'parallel' of latitude on the earth, then it is a circle that proceeds east and west from any point on it. There can be any desired number of them, the only specification being that every point on the 'parallel' has the same geographic latitude. Since these are all curved lines, it's hard to say that they are parallel in the same sense as parallel straight lines on a flat surface. But the planes they lie in are all truly parallel planes.
No, parallel lines are straight lines.
a circle
No. The circular shape makes it impossible to have parallel lines just as you cannot have parallel lines in a circle that both reach the length of the diameter of the said circle.
None.
No because it is just a circle.
Parallel lines within a circle are infinite.
a semi - circle has zero parallel lines
circle
The two points on exactly opposite sides of a circle are parallel to each other. This can be evidenced by finding the derivative/gradient at those points; if they are the same then the two line segments described by those points are parallel.
None
Cdm
Yes it does