Assertion: tetrahedron | /r/HasAspect | triangular base
Facets:
Source sentences:
text: As you can see from the illustration below, the tetrahedron has a triangular base (any one of the tetrahedron's four faces can be designated to be the base), and three triangular sides that connect the base to the apex.
text: A tetrahedron has a triangular base and shares edges with 3 other triangular faces, who all share a common "top" vertex (and thus two edges each).