Question

A person observes the angle of deviation of a building as $30 ^ { \circ }$. The person proceeds towards the building with a speed of $45 ^ { \circ }$. The height of the building (in metres) is

• A. 100
• B. 50
• C. $50 ( \sqrt { 3 } + 1 )$
• D. $50 ( \sqrt { 3 } - 1 )$

Answer 1

Answer: (B)

50

Answer 2

In $\Rightarrow$ $\frac { 1 } { \sqrt { 3 } } = \frac { h } { 50 ( \sqrt { 3 } - 1 ) + h }$

$\sqrt { 3 } h = 50 ( \sqrt { 3 } - 1 ) + h$

⇒ $h = 50$ metre