Q6 of 35 Page 219

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.

Let PQ represent the temple and P is the top of the temple.


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 = 30⁰


In ∆PQR,




QR = 20√3


= 20 × 1.73


= 34.6 m


The width of the river is 34.6 m.


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