question_answer

When a plane mirror is placed horizontally on a level ground at a distance of 60 metre from the foot of a tower. The top of the tower and its image in the mirror subtend at the eye an angle of \[{{90}^{o}}\], the height of the tower is:

A)  \[30\,m\]           

B)                         \[40\,m\]           

C)         \[60\,m\]           

D)                         \[90\,m\]

Correct Answer: C

Solution :

\[\tan 45=\frac{h}{60}\] \[1=\frac{h}{60}\]            \[\therefore \]  \[h=60m\] Height of tower is 60 m.