CBSE 10th Class past year question paper
Year 2019
SET 1, Code Number- 30/2/1
Question number – 24
Deepak BoraNewbie
Amit, standing on a horizontal plane, finds a bird flying at a distance of 200 m from him at an elevation of 30°. Deepak standing on the roof of a 50 m high building, finds the angle of elevation of the same bird to be 45°. Amit and Deepak are on opposite sides of the bird. Find the distance of the bird from Deepak.
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In ∆APQ
PQ/AP = sin 30º = 1/2
PQ = (200)(1/2)
= 100 m
PR = 100 – 50
PR = 50 m
In ∆PRD,
PR/PD = sin 45° = 1/√2
PD = (PR)( √2)
= 50 √2 m