A dihedron is a regular tiling or map on a sphere composed of two regular 
-gons, each occupying a hemisphere and with edge lengths of
on a unit sphere. Its Schläfli
symbol is 
.
Its dual is the hosohedron 
.
Dihedron
See also
Digon, HosohedronExplore with Wolfram|Alpha
References
Coxeter, H. S. M. Regular Polytopes, 3rd ed. New York: Dover, p. 12, 1973.Referenced on Wolfram|Alpha
DihedronCite this as:
Weisstein, Eric W. "Dihedron." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Dihedron.html