Assertion: icosahedron's edge | /r/CapableOf | share common vertex
Facets:
Source sentences:
text: If two edges share a common vertex, then the midpoints of those edges form a 36-72-72 triangle with the body center.
text: The face normals (normalized cross products of edges that share a common vertex) of the 6 square faces are (0, 0, ±1), (0, ±1, 0) and (±1, 0, 0).