Adistance along a line must have no beginning or end.

A line continues forever without a point. It has no beginning or end. But, to answer your question it is most likely there is no end to a line.

This is true.  In geometric terms, a line is a set of values that extends forever in two directions on a flat plane with no beginning or end.  Hope this helps!

(Extra info:  A ray is a line that extends forever in one direction on a flat plane, and it has a beginning, but no end.  A segment is a line that does not extend forever in any direction because a segment has a beginning and an end.)