Law of Reflection: Angle of Incidence Equals Angle of Reflection

Steps:

• Measure the angle of incidence between the incident ray and the normal to the mirror surface.
• Note that the diagram shows this angle as 60°.
• Apply the law of reflection, which states the angle of reflection equals the angle of incidence.
• Determine the angle of reflection is 60°.

Why B is correct:

• The law of reflection requires the angle of reflection to match the 60° angle of incidence shown in the diagram.

Why the others are wrong:

• A: 30° would imply an incidence angle half of the actual 60°, violating the equality law.
• C: 90° represents a grazing reflection, not matching the 60° incidence.
• D: 120° exceeds 90° from the normal, impossible for reflection off a plane mirror.

Final answer: B