Assertion: icosahedron's face | /r/HasProperty | d f \displaystyle d_{f
Facets:
Source sentences:
text: A modified form of Euler's formula, using density (D) of the vertex figures ( d v {\displaystyle d_{v}} ) and faces ( d f {\displaystyle d_{f}} ) was given by Arthur Cayley, and holds both for convex polyhedra (where the correction factors are all 1), and the Kepler–