Why can’t a flat mirror be used as a movie screen?

A flat mirror cannot be used as a screen, as we will see the film image in the projection lamp at a distance 2 times greater than the distance from the film to the screen.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.