It is an imaginary line that produces a mirror image of a shape which is its line of symmetry
There is no such thing. An axis (plural = axes) of symmetry (not symmerty) for any plane figure is a line which divides the figure into two shapes that are mirror images of one another.
180 degrees
1
4
Yes
Three
Order 4.
It would help if you checked your spelling before posting the question. I can guess that "symmerty" is meant to be symmetry but I have no idea what a hepaton is. Sorry.
No. But it does have rotational symmetry of order 2.
bilaterally symmetry
Yes, of order 2.