The line of reflection.
The angle of incidence is the angle between a perpendicular and the line of incidence; and the angle of reflection is the angle between the perpendicular and the line of reflection. The two angles are always equal to each other, as is represented in [Fig. 8].
Fig. 8.
When a ray of light strikes a looking-glass obliquely or slantingly, what is done with it?
The ray is reflected as obliquely from the glass as it strikes or falls upon it.
Why is the reflection of the sun in a pond of water seen near the edge at noon?
Because the angle of reflection is equal to the angle of incidence; and the observer must be nearly over the place where the rays strike, so that, when reflected, they may meet his eye.
Where is the reflection seen in the morning or in the evening?
It is seen nearer the middle of the pond; because the sun’s rays then fell more obliquely on the pond, and are reflected more obliquely to the eye.