Assertion: tetrahedron | /r/HasAspect | $12$ rotations
Facets:
Source sentences:
text: The tetrahedron has $12$ rotations: you can rotate it $120^o$ either way about an axis passing through a vertex and the center of the opposite face, $8$ of those; or $180^o$ about an axis through two opposite edges, $3$ of those; or the $0^o$ identity rotation.