1. A polyhedron has 6 vertices and 9 edges. How many faces does it have?
a. 3
b. 5
c. 7
d. 9
2. A polyhedron has 25 faces and 36 edges. How many vertices does it have?
a. 11
b. 12
c. 13
d. 14
V - number of vertices, E - number of edges, F - number of faces: Euler`s polyhedron formula: V - E + F = 2 1. F = E - V + 2 F = 9 - 6 + 2 = 5 Answer: A ) 5 2. V = E - F + 2 V = 36 - 25 + 2 = 13 Answer: C ) 13