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).
See the other axes of symmetry and see all the axes of symmetry together.
©
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