From a point on one bank of a river

MATHEMATICS · Single correct · CBSE · Mathematics · Applications of Trigonometry · Applications of Trigonometry

Problem

From a point on one bank of a river, the angle of elevation of the top of a tree on the opposite bank is

30^{\circ}

. If the height of the tree is 12 m, calculate the width of the river.\,(Take

\tan 30^{\circ}=\tfrac1{\sqrt{3}}

; give your answer to one decimal place.) (a) 13.9 m (b) 20.8 m (c) 6.9 m (d) 24.0 m