Height and DistanceHard
Question
A person standing on the bank of a river observes that the angle of elevation of the top of a tree on the opposite bank of the river is 60o and when he retires 40 meter away from the tree the angle of elevation becomes30o . The breadth of the river is
Options
A.20 m
B.30 m
C.40 m
D.60 m
Solution
tan 30o
⇒ √3 h = 40 + b .....(1)
tan60o = h/b ⇒ h = √3 b ....(2)
⇒ b = 20 m
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