Question

As observed from a fixed point on the bank of a river, the angle of elevation of a temple on the opposite bank has measure 30. If the height of the temple is 20 m, find the width of the river.

Answer 1

We,know angle of elevation is 30 degree

and height of temple is 20 m

Let, the width of the river is x m.

On solving as shown in attachment we got x is 20√3 m .

Answer 2

Let PQ represent the temple where P is the top of the temple. given, PQ = 20 m
R is a fixed point on the bank of a river from a temple on the opposite bank and QR is the width of the river.

∠PRQ = 30°

In ∆PQR,

cot30° = QR/PQ

√3 = QR/20

QR = 20√3 m

hence , width of the river is 20√3 m