Assertion: polyhedron's face | /r/HasProperty | parts of planes
Facets:
Source sentences:
text: In geometry, a polyhedron is traditionally a three-dimensional shape that is made up of a finite number of polygonal faces which are parts of planes; the faces meet in pairs along edges which are straight-line segments, and the edges meet in points called vertices.
text: A Polyhedron is a closed plane figure whose faces are portions of planes.