Question

If the ratio of the length of a pen to its shadow is $1:\sqrt{3}$, the angle of elevation of the source of light is:

• A. ${40}^{\circ }$
• B. ${30}^{\circ }$
• C. ${60}^{\circ }$
• D. ${90}^{\circ }$

Answer 1

Answer: (B)

${30}^{\circ }$

Given$:$Length of the pen to the shadow$1:\sqrt{3}$

Note: Length of the pen is the height(perpendicular) and length of the shadow is the length of the base. The angle of inclination has to be calculated.

then $\tan \theta =\frac{perpendicular}{base}=\frac{1}{\sqrt{3}}$

$\Rightarrow \theta ={30}^{\circ }$