13.1.8. Construct an image of the object in a dihedral mirror with an angle at the vertex of $90^\circ$. How does this image differ from the image in a flat mirror? The mirror is located in the corner of the room. From what points in the room can you see your image?
Solution
For problem $13.1.8$
While there are images created by a single reflection at each mirror, we are interested in the image created by two consecutive reflections at both mirrors. An observer at $A$ can see such an image of point $B$ at $B\,''$, while an observer at $B$ can see such an image of point $A$ at $A''$. Such images can be observed from anywhere in a rectangular room. Unlike the images created by a single reflection (such as those at $A'$ and $B\,'$, the image created by two consecutive reflections are not inverted (or doubly inverted). Note that the image of point $A$ at $A^*$ is not observable by the observer at $B$, but may be observed from other positions.
