[math-fun] Johnson solids trivia challenge

Mathematica knows all 92. (Regular polygonal faces, dihedrals < π, not ordinary prisms.) Name any of the four with largest dihedral. According to ries, that angle satisfies sinpi(sin(x)) = cospi(1/sqrt(6)).! —rwg Spoiler: (Kids: Don't peek! This is a nice exercise.) StringReverse@"]&]]\"selgnAlardehiD\",#[ataDnordehyloP[xaM@N ,][ataDnordehyloP[yBlamixaM@/&]#,#@ataDnordehyloP[delebaL" —rwg Gotcha: Why does this fail without the N@? Easy questions: Why disallow dihedrals > π (concavities)? Invisible edges with dihedral = π?