6) tetrahedron 3|2 3 [15,1]
dual: tetrahedron
(3.3.3), tetrahedral group A4, χ=2, D=1
V=4, E=6, F=4=4{3}
α γ a b c ρ/R r/ρ l/ρ h/r
{3} 60.0 60.0000 54.74 70.53 54.74 0.577350 0.577350 1.414214 1.414214