question_answer

The angle of elevation of the top of a tree from a point A on the ground is \[60{}^\circ \]. On walking 20 m away from its base, to a point B, the angle of elevation changes to \[30{}^\circ \]. Find the height of the tree.

A)  \[10\,\sqrt{3\,}m\]

B)  \[20\,\sqrt{3\,}m\]

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

D)  \[40\,\sqrt{3\,}m\]

E)  None of these