In the given figure; AB is a mirror, PQ is the incident ray and QR is the reflected ray. If ∠PQR=108∘ then ∠AQP=?
(a)72∘
(b)18∘
(c)36∘
(d)54∘
ANSWER:
(c)36∘
We know that angle of incidence = angle of reflection.
Then, let ∠AQP=∠BQR=x
Now,
∠AQP+∠PQR+∠BQR=180∘∵AQBisastraightline⇒x+108+x=180∘⇒2x=72°⇒x=36∘∴∠AQP=36∘