Subject: must the number of virtual images formed by the plane mirrow be an odd one?

i know that if 2 plane mirrows are inclined for example at 90 degrees only 3 
virtual imager will be formed.A friend of mine told me that the number of 
images formed by a plane 
mirrow is 
given by [360/o + 1]where o represents the angle of inclination of the 
plane 
mirrow. He told me that if  360/o gives me an odd number, i should not 
subtract 
1 from it.He told me that the number of images formed by a plane mirow 
must be 
an odd number.I want the organisation to verify the validity of this 
statement

Re: must the number of virtual images formed by the plane mirrow be an odd one?