A polyhedron with 20 faces and 30 edges has ___ vertices.
10
11
12
13
F = 20, E = 30, V = ?
Using Euler's formula we get
F + V - E = 2
20 + V - 30 = 2
V - 10 = 2
V = 12
Hence (C)
A polyhedron with 20 vertices and 30 faces has ___ edges.
If a polyhedron has 15 vertices and 20 edges, then it has ___ faces.