Explain how, a hair dresser makes you see hair at the back of your head after the hair cut is complete.

Dear student, 

Hair dresser uses the phenomena of multiple reflection to provide view of the back of the head to the customer.This can be made by letting you stand in front of the mirror and holding up another mirror behind your head. I doing so the reflection of the back of the head can be seen in the mirror in front of you.

Hope this clears your doubts. Post again for further queries.
Regards