waecmaths question:
A boy looks through a window of a building and sees a man fruits on the ground 50 m away from the foot of the building. If the windows is 9m from the ground. Calculate, correct to the nearest degree, the angle of depression of the mango from windows
Option A:
9o
Option B:
10o
Option C:
11o
Option D:
12o
waecmaths solution:
$\begin{align} & \angle ABC=\angle DCB=\theta \text{ }\{\text{ Alternate angles }\}\text{ } \\ & \tan \theta =\frac{opp}{adj}=\frac{AC}{AB}=\frac{9m}{50m} \\ & \tan \theta =0.18 \\ & \theta ={{\tan }^{-1}}(0.18)={{10.2}^{{}^\circ }} \\ & \text{To the nearst degree, the angle of depression is }{{10}^{\circ }} \\\end{align}$
maths year:
maths topics: