WAEC - Mathematics (2019 - No. 37)
From the top of a vertical cliff 20m high, a boat at sea can be sighted 75m away and on the same horizontal position as the cliff. Calculate, correct to the nearest degree, the angle of depression of the boat from the top of the cliff.
56\(^o\)
75\(^o\)
16\(^o\)
15\(^o\)
คำอธิบาย
Sin\(\theta = \frac{20}{75}\)
\(\theta = sin^{-1} (\frac{20}{75})\)
= 15\(^o\)