Does an exact three-fold symmetry exist in physics?

[Loren Booda]

An isolated electron and positron depict an exact two-fold symmetry. Are there any examples in physics of a truly triplicate symmetry? If not, what constraints are there that prevent it?

 

[Loren Booda]

How about that for baryons composed of three identical quarks?

 

[Mentz114]

To be very picky, the electron/positron symmetry is an exact anti-symmetry like the anti-symmetry between E and B in EM. The spinor wave equation pair have a change of sign, or they would be symmetrical.

I've been told I'm a pedant already.

 

[Parlyne]

How about the color charges of quarks?

 

[vanesch]

cyclic rotation of x y and z axis in space ?