A polyhedron has 20 faces and 30 edges.How many vertices does it have?

Let V be the number of vertices in the polyhedron.

According to Euler's formula for polyhedra: V - E + F = 2

Where:
V = number of vertices
E = number of edges
F = number of faces

Given that the polyhedron has 20 faces and 30 edges, we can substitute these values into the formula:

V - 30 + 20 = 2
V - 10 = 2
V = 2 + 10
V = 12

Therefore, the polyhedron has 12 vertices.

26