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Question
Find the angle of depression from the top of a 140m high pillar of a milestone on the ground at a distance of 200m from the foot of the pillar.
Solution
Let AB be the pillar. Let the angle of depression be θ.
In triangle ABC,
`tanθ = "AB"/"BC"`
⇒ `tanθ = 140/200 = 7/10 = 0.7`
We have : `tan 35^circ = 0.7`
Thus , the angle of depression is θ = 35°.
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