An icosahedron is a regular polyhedron with how many faces?

• A. 12
• B. 20
• C. 30
• D. 50

Answer: (B)

An icosahedron is characterized by its geometric properties, particularly the number of faces it has. It is one of the five Platonic solids, which are defined by being convex, with faces that are identical regular polygons. Specifically, an icosahedron consists of 20 triangular faces. This unique configuration allows for each vertex of the icosahedron to be surrounded by five faces, emphasizing its symmetry and regularity.

The other options inaccurately represent the total number of faces found in other polyhedra or blended forms. For instance, a dodecahedron, another Platonic solid, has 12 faces, while variations of polyhedra can have more faces, such as the numerous combinations seen in higher dimensions. However, the defining trait of the regular icosahedron is its precise count of 20 faces.