Kaleidoscopes
The three 3D kaleidoscopes. If we ignore the cases with two right angles, there are three ways to build a spherical kaleidoscope; each angle must be an integer divisor of 180°, so the three possibilities are: a spherical triangle with angles 90°, 60°, 60°, corresponding to the regular tetrahedron; one with angles 90°, 60°, 45°, corresponding to cube and regular octahedron; one with angles 90°, 60°, 36°, corresponding to regular icosahedron and dodecahedron.
Exhibit from Simmetria, giochi di specchi - Symmetry, playing with mirrors.
© matematita
The image belongs to the sections...:
From "mirrors" (From "XlaTangente")
The objects (From the exhibitions of matematita)
Further information:
http://specchi.mat.unimi.it