An observer whose eye is 1.5 m above the ground stands 40 m from the foot of a tower. The angle of elevation of the top of the tower is 45°. How tall is the tower?
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Hint
The angle gives the height above the eye; add the eye height.
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Answer: D. 41.5 m
H = h + l tan α = 1.5 + 40 × tan 45° = 1.5 + 40 = 41.5 m. The eye height is added because the angle is measured from the eye, not from the ground.