From the top of a building 20 m high, the angle of elevation of the top of a monument is 45° and the angle of depression of its foot is 15°. Find the height of the monument.
Heights & Distances
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Question

From the top of a building 20 m high, the angle of elevation of the top of a monument is 45° and the angle of depression of its foot is 15°. Find the height of the monument.

KnowledgeBoat · Accepted Answer

Let AB be the building and CD be the monument. Let length of monument (CD) be h metres. Let distance between building and monument (BD) be x meters. From figure, ABDE is a rectangle so, DE = AB = 20 meters AE = BD = x meters CE = CD - DE = (h - 20) meters ∠EAD = ∠ADB = 15° Considering right angled △ABD we get, Considering right angled △ACE we get, Hence, the height of the monument is 94.65 meters.

Mathematics

From the top of a building 20 m high, the angle of elevation of the top of a monument is 45° and the angle of depression of its foot is 15°. Find the height of the monument.

Heights & Distances

Related Questions

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