Illustration showing a trigonal dodecahedron.

Trigonal Dodecahedron

Illustration showing a trigonal dodecahedron.

"...bounded by six isosceles triangles...indices as in the hexagonal bipyramid." -The Encyclopedia Britannica 1910

Trigonal Bipyramid

"...bounded by six isosceles triangles...indices as in the hexagonal bipyramid." -The Encyclopedia Britannica…

"...bounded by six trapezoidal hedra...derivable from the scalenohedron." -The Encyclopedia Britannica 1910

Trigonal Trapezohedron

"...bounded by six trapezoidal hedra...derivable from the scalenohedron." -The Encyclopedia Britannica…