question_answer

A man looks from the top of a vertical tower 30 metres high at a marked point upon the horizontal plane on which the tower stands. The angle of depression of this point is \[30{}^\circ \]. The distance of the marked point from the foot of the tower is

A) \[\frac{30}{\sqrt{3}}m\]

B)   \[\frac{30\sqrt{3}}{2}m\]  

C) \[30\,\,m\]

D) \[30\sqrt{3}\,\,m\]

Correct Answer: D

Solution :

 \[\frac{OP}{OM}=\cot \,{{30}^{o}}\] or            \[OP=30\sqrt{3}\,m\]