Assertion: tetrahedron's ax | /r/CapableOf | join each vertex
Facets:
value: to its opposite face
type: TRANSITIVE-OBJECT
Source sentences:
text: The regular tetrahedron defines two sets of symmetry axes: one set of 4 3-fold axes that join each vertex to its opposite face, and one set of 3 2-fold axis that join the middle of opposite edges.