The rotations of the tetrahedron
The blue straw, laid between the mirrors that form an angle of 60°, shows the 4 rotation axes of order 3 in a regular tetrahedron (the lines that go through a vertex and the centre of the opposite face).
See the other axes of symmetry and see all the axes 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)