Basic Solids

In geometry the basic three dimensional objects can be classified according to whether they have flat surfaces or curved surfaces.

A three-dimensional shape whose faces are polygons is known as a polyhedron. This term comes from the Greek words poly, which means "many," and hedron, which means "face." So a polyhedron is a three-dimensional object with many faces.  The faces are polygons whose sides are edges and whose vertices are vertices of the polyhedron.  Cubes and pyramids are examples of polyhedra (plural of "polyhedron"):

The standard objects with curved surfaces are cylinders, cones and spheres:

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