In a circle, any diameter is an axis of symmetry, so technically a cirle should have infinitely many axes of symmetry.
This got me thinking about the axes of symmetry of straight lines. A line segment obviously has only one axis of symmetry, but what about an unbounded infinite straight line?
Does it have one axis of symmetry (seems unlikely), infinitely many, none at all? Does it depend on the kind of Geometry we're talking about?