Describe and Make Regular and Non Regular Polyhedra

Is the solid a polyhedron? If so, is it convex? Regular?

definitions:

polyhedron: solid bounded by polygons

convex: if any two points on its surface can be connected by a segment that lies                                                                                                                                                      entirely inside or on the polyhedron

regular: all faces are congruent regular polygons

A)

• • polyhedron
  • convex
  • regular

B)

• • not polyedron
  • convex
  • non-regular

C)

• • polyhedron
  • non-convex
  • non-regular