Show that the minimum size of a plane mirror required to see the full image of an observer is half the size of that observer.

Explanation

The total height of the person from top of the head T to bottom of the feet F is TF. E. is exactly appropriate to E, the eye level of the person.
From the foot F, the incident ray is reflected at B, the level end of the mirror to reach the eye level of the person at E. Due to incident ray equal to reflected ray, as shown by `theta`.
`E.B=(1)/(2)EF=(h_(1))/(2)`
A similar argument proves `AE.=(1)/(2)TE=(h_(2))/(2)`
Here height of the mirror to show a full-sized image of the person is only half sized i.e.,
`AB=AE.+E.B=(h_(1))/(2)+(h_(2))/(2)=(h_(1)+h_(2))/(2)`