Why are cylinders and cones not considered to be polyhedrons?

Answer 1

Cylinders and cones are not considered polyhedrons because they do not have flat faces, which is a defining characteristic of polyhedrons. Polyhedrons are three-dimensional shapes made up of flat surfaces, while cylinders and cones have curved surfaces. Additionally, polyhedrons have straight edges where faces meet, whereas cylinders and cones have curved edges. Therefore, cylinders and cones are classified as curved surfaces rather than polyhedrons.

Answer 2

A polyhedron is defined as a "geometric solid in three dimensions with flat edges and straight faces". As both cylinders and cones have curved faces, neither are polyhedra.