Question

What is the angle of elevation of a vertical flagstaff of height $100\sqrt{3}m$ from a point $100m$ from its foot.

• A. ${18}^o$
• B. ${30}^o$
• C. ${48}^o$
• D. ${60}^o$

Answer 1

The correct option is D ${60}^o$

Height of flagstaff (H) = $100\sqrt{3}$
Distance between the point and the flagstaff (D) = 100 m
Let the angle of elevation be $\theta$
Then,
$\tan \theta =\frac{D}{H}$
$\tan \theta =\frac{100\sqrt{3}}{100}$
$\tan \theta =\sqrt{3}$
$\tan \theta =\tan {60}^{\circ }$
$\theta ={60}^{\circ }$