question_answer

An observer in a boat finds that the angle of elevation of a tower standing on the top of a cliff is 60o and that of the top of cliff is 30o. If the height of the tower be 60 meters, then the height of the cliff is [Roorkee 1982]

A) 30 m

B) \[60\sqrt{3}\,\,m\]

C) \[20\sqrt{3}\,\,m\]

D) None of these

Correct Answer: A

Solution :

\[(60+h)\cot {{60}^{o}}=h\cot {{30}^{o}}\]\[\Rightarrow \] \[h=30m\]