How many symmetrical lines can be drawn on a line segment, line, angle, Arrow head?

If AB is a line segment, then a line l, which is the perpendicular bisector of AB, is the line of symmetry. But if it would have been a line then it could have infinitely many LOS as it does not has a fixed length.
So, a line segment has one line of symmetry and a line has infinitely many lines of symmetry.
The line of symmetry for an angle is its bisector.
So, an angle has one line of symmetry.
An arrowhead has only one line of symmetry ( figure below)


Regards!