Question

Let two plane mirrors are inclined at an angle theta.
Total deviation produced from two inclined plane mirror after two successive reflection is given by delta=360-2theta

The number of images formed n=(360/theta)-1, if (360/theta) is even integer..

If (360/theta) is odd integer, the number of images formed n=(360/theta)-1 when the object is kept symmetrically, and n=(360/theta) when object is kept asymmetrically..

If (360/theta) is a fraction, the number of images formed is equal to its integral part..

Now, my question is: how do we get these relations?