1) pentagonal prism 2 5|2 dual: pentagonal dipyramid (4.4.5), dihedral group D5, χ=2, D=1 V=10, E=15, F=7=2{5}+5{4} α γ a b c ρ/R r/ρ l/ρ h/r {5} 36.0 69.7882 30.45 59.55 54.00 0.862104 0.587785 0.587785 1.376382 {4} 45.0 55.1059 30.45 45.78 36.00 0.862104 0.809017 0.587785 0.726543