Question

The angle of elevation of the sum when the length of the shadow of a tower is equal to its height is:

• A. ${30}^o$
• B. ${45}^o$
• C. ${60}^o$
• D. ${90}^o$

Answer 1

Answer: (B)

${45}^o$

$\overline{AB}$ is a building and $\overline{BC}$ is its shadow.
Given that the height of a building and the length of its shadow are equal.
$\therefore AB=BC$
Let the angle of elevation of the sun is $\theta$.
In $△ABC,\tan \theta =\frac{AB}{BC}$
$\therefore \tan \theta =1(\because AB=BC)$
$\therefore \theta ={45}^{\circ }$
So, the angle of elevation of the sun is ${45}^{\circ }$.