(i) the angle of incidence
(ii) the angle of reflection
ON is normal on the plane mirror at point O
ON is perpendicular on a plane mirror
Angle of incidence ∠i = ∠AON
and angle of reflection ∠r = ∠BON
Since, ∠i – ∠r
∠AOB = 30°
⇒ ∠AON + ∠BON = 30°
⇒∠i + ∠i – 30°
⇒ 2 ∠i =30°
⇒ ∠i = 30 / 2 = 15°
∴Angle of incidence = ∠i = 15°
and Angle of reflection ∠i = 15°