A person was standing on a road near a mall. He was 1215 m away from the mall and able to see the top of the mall from the road in such a ways that the top of a tree, which is in between him and the mall, was exactly in line of sight with the top of the mall. The tree height is 20 m and it is 60 m away from him. How tall (in m) is the mall?

Answer: Option C

Solution

Answer: Option C

Solution:

$$\begin{array}{rl}& \tan \theta =\frac{20}{60}=\frac{1}{3}\\ & \text{Now }\tan \theta =\frac{h}{1215}\\ & \frac{1}{3}=\frac{h}{1215}\\ & h=405\end{array}$$