From the top of a 120 m high tower, the angle of depression of the top of a pole 45° and the angle of depression of the foot of the pole is θ, such that tan θ = 3/2, what is the height of the pole?
From the top of a 120 m high tower, the angle of depression of the top of a pole 45° and the angle of depression of the foot of the pole is θ, such that tan θ = 3/2, what is the height of the pole? Correct Answer 40 m
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Given, tan θ = 3/2
From the following figure
Height of the Tower AB = 120 m
Height of the pole = EC
DE = BC and BD = EC
In ΔABC
tan θ = AB/BC
3/2 = 120/BC
BC = 80 cm
DE = BC = 80 cm
In ΔAED
tan 45° = AD/DE
1 = AD/DE
AD = 80 m
AB = BD + DA
120 = BD + 80
BD = 120 - 80 = 40 m
Hence, height of the pole is 40 m
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Feb 20, 2025