Law of Reflection in Plane Mirrors

Steps:

• Draw the normal perpendicular to the mirror surface at the point of incidence.
• Angle X is the angle between the incident ray and the normal (angle of incidence).
• Angle Y is the angle between the reflected ray and the normal (angle of reflection).
• The law of reflection requires X = Y for the rays on opposite sides of the normal.

Why C is correct:

• The \ symbol matches the diagram's normal orientation, and X = Y follows the law of reflection where incidence equals reflection.

Why the others are wrong:

• A: / symbol mismatches the diagram's normal slant, invalidating X = Y.
• B: / symbol is wrong, and X + Y = 90° confuses with complementary angles, not reflection law.
• D: \ symbol is correct, but X + Y = 90° incorrectly implies perpendicular rays instead of equal angles.

Final answer: C