51. Exemplar exercise problems XVI

The image of an object placed at a point \(A\) before a plane mirror \(LM\) is seen at the point \(B\) by an observer at \(D\) as shown in the below figure. Prove that the image is as far behind the mirror as the object is in front of the mirror.

 

 

[Hint: \(CN\) is normal to the mirror. Also, angle of incidence \(=\) angle of reflection].