Which of the following is a polyhedron? check all that apply.
a. prism
b. pyramid
c. cone
d. polygon

A polyhedron is three dimensional solid that only has flat faces. It contains vertices and straight edges. From the choices, the solids that would be considered as polyhedron are prism and pyramid. A cone cannot be considered as such since it containsa round surface. A polygon is a two dimensional shape thus it does not satisfy the condition of a polyhedron.