a ray of light incident on a plane mirror at an an angle @.

SO whats the meaning of this sentence..........angle between ray and mirror is @

or............angle of incidence is @

This Means Angle b/w Normal To The Mirror At the point The Ray is Striking and The Ray Itself.

this means that if u draw a perpendicular line (normal) to plane mirror then angle bw incident light

& normal is @...