Question

Two mirrors are placed at an 45° angle with each other , number of images formed by them and why?

Answer 1

The formula for number of images formed by two plane mirrors placed at certain angle is (360/n).[where n=angle between the mirrors]

The most important thing to remember is that, every time the number of images formed are only ODD numbers.

if the result is even then you need to subtract 1 from that.

if it is odd u need not subtract , since the number of images ever formed are only odd.  so for the angle 45 degrees the number of images formed are:

360/45

=8  

in this case, since the images formed are even u need to subtract 1 from it i.e

8–1

=7

so the number of images formed are 7.