waecmaths question:
An object is 6m from the base of a mast. If the angle of depression of the object from the top of the mast is 50o, find, correct to 2 decimal places, the height of the mast
Option A:
8.60m
Option B:
7.83m
Option C:
7.51m
Option D:
7.15m
waecmaths solution:
$\begin{align} & \angle BCA=\angle DAC\text{ }\!\!\{\!\!\text{ Alternate angles }\!\!\}\!\!\text{ } \\ & \text{tan5}{{\text{0}}^{\circ }}=\frac{AB}{6m} \\ & AB=6m\tan {{50}^{\circ }}=6m\times 1.1918=7.15m\text{ to 2d}\text{.p} \\\end{align}$
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