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From the top of a 100 m high lighthouse, the angle of depression of a boat is 30°. The distance of the boat from the foot of the lighthouse is:

Answer: B

The angle of depression from the top of the lighthouse to the boat is equal to the angle of elevation from the boat to the top of the lighthouse.

Let the distance of the boat from the foot of the lighthouse be 'd'.

\(\tan 30° = \frac{\text{height}}{\text{distance}} = \frac{100}{d}\)

\(\frac{1}{\sqrt{3}} = \frac{100}{d}\)

d = 100√3 meters.

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