The rotations of the tetrahedron
The green straw, laid between the two mirrors that form an angle of 90°, shows the 3 rotation axes of order 2 in a regular tetrahedron (the lines that go through the midpoints of two opposite edges); the blue straw, laid between the mirrors that form an angle of 60°, shows the 4 rotation axes of order 3 (the lines that go through a vertex and the centre of the opposite face).
©
The image belongs to the sections...:
The symmetry group of the tetrahedron
(*332) (Symmetry)
In the yellow kaleidoscope (tetrahedron) (From the exhibitions of matematita)
Tetrahedron (3D geometry)
Further information:
http://specchi.mat.unimi.it
