Assertion: icosahedron's edge | /r/CapableOf | join vertex
Facets:
Source sentences:
text: And the edges are the long line segments joining the vertices.
text: Assume the edges are sitting at vertices $
text: e e is a 1 / 2 1/2 turn around the center of an edge touching that vertex,
text: Let q be the number of edges that meet at every vertex.