Question

A mirror 1 mhigh hangs on a wall. A man stands a distance of 2 m away from the mirror. What is the height of the portion of the opposite wall in the room that can be seen by the man in the mirror without changing the position of his head? The wall is 4 m from the mirtor

• A. 3m
• B. 4m
• C. 3.5m
• D. None of these

Answer 1

Answer: (A)

3m

The man is standing at point $A$.

From the figure we can say that $\Delta ABC$ and $\Delta ADE$ are similar triangles.

Hence, $\frac{AC}{AE}=\frac{BC}{DE}$

$\Rightarrow \frac{2}{2+4}=\frac{1}{DE}$

$\Rightarrow DE=\frac{6}{2}=3m$

Hence the correct answer is option (A).