From the top of a tower 100 m high, a man observes the angle of depression of two ships A and B, on opposite sides of the tower as 45° and 38° respectively. If the foot of tower and the ships are in the same horizontal line, find the distance between two ships A and B to the nearest metre.

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Let CD be the tower.
From figure,
⇒ ∠A = ∠EDA = 45° (Alternate angles are equal)
⇒ ∠B = ∠FDB = 38° (Alternate angles are equal)
In △ ACD,
⇒ tan A = $\frac{CD}{AC}$
⇒ tan 45° = $\frac{100}{AC}$
⇒ AC = $\frac{100}{\text{tan 45°}} = \frac{100}{1}$ = 100 m.
In △ BCD,
⇒ tan B = $\frac{CD}{BC}$
⇒ tan 38° = $\frac{100}{BC}$
⇒ BC = $\frac{100}{\text{tan 38°}} = \frac{100}{0.7813}$ = 127.99 m.
From figure,
The distance between ships A and B = AC + BC
= 100 + 127.99
= 227.99 m ≈ 228 m.
Hence, the distance between the two ships A and B = 228 m.