The three mirror boxes
There are only three ways to build a triangular mirror box; each angle must be an integer divisor of 180°, so the three possibilities are: an equilateral triangle, a triangle with angles 90°, 45°, 45°, a triangle with angles 90°, 60°, 30°.
Exhibit from Simmetria, giochi di specchi - Symmetry, playing with mirrors.
The image belongs to the sections...:
The objects (From the exhibitions of matematita)