Question

When the length of the shadow of the pole is equal to the height of the pole, then the elevation of the source of light is

(a) 30° 

(b) 45° 

(c) 60° 

(d) 75°

Answer 1

Let PQ be the pole, QR be its shadow. Let L be the source of light and q be the angle of elevation of the source of light, such that 

PQ = QR ∴ ∠PRQ = θ

∴ In rt. Δ PQR

\(\frac{PQ}{QR}\) = tan θ ⇒ tan θ = 1

⇒ θ = 45°. 

∴ Required angle of elevation = 45°