question_answer

The angle of elevation of the top of a lamp-post as observed from a point 40 m distant from the foot of the post, is \[30{}^\circ \]. The height of the lamp post is

A)  \[40\sqrt{3}m\]          

B) \[\frac{40\sqrt{3}}{3}m\]  

C) \[20 m\]

D) \[\frac{40\sqrt{3}}{2}m\]