Great Truncated Icosahedron

The Uniform Polyhedron $U_{55}$, also called the Truncated Great Icosahedron, whose Dual is the Great Stellapentakis Dodecahedron. It has Schläfli Symbol t $\{3,{\textstyle{5\over 2}}\}$ and Wythoff Symbol $2\,{\textstyle{5\over 2}}\,\vert\,3$. Its faces are $20\{6\}+12\{{\textstyle{5\over 2}}\}$. Its Circumradius for unit edge length is

$$R={\textstyle{1\over 4}}\sqrt{58-18\sqrt{5}}\,.$$

References

Wenninger, M. J. Polyhedron Models. Cambridge, England: Cambridge University Press, p. 148, 1989.