A light ray approaches a mirror at an angle of 22° with the mirror surface. What is the angle of reflection of this light ray?
With a flat mirror the angle of incidence is equal to the angle of reflection.
These are angles with the vertical axis perpendicular to the surface of the mirror passing through the point of incidence.
In your case:
The dotted line is the vertical axis.
If you have the angle of 22° with the mirror surface the angle of incidence will be: