31. They, however, excluded the described here icosahedron -based rare-earth borides. 32. The B1 sites form one icosahedron and the B2 B9 sites make up another icosahedron. 33. The B1 sites form one icosahedron and the B2 B9 sites make up another icosahedron . 34. Many viruses, such as the herpes virus, have the shape of a regular icosahedron . 35. Its vertex figure is an icosahedron , and its dual polytope is the 120-cell. 36. A Roman icosahedron has also come to light after having long been misclassified as a dodecahedron. 37. The two pentagonal faces of either shape can be augmented with pyramids to form the icosahedron . 38. Its dual, the great icosahedron , is related in a similar fashion to the icosahedron. 39. Its dual, the great icosahedron, is related in a similar fashion to the icosahedron . 40. The icosahedron formed by the B1 site atoms is located at the center of the supericosahedron.
