Polyhedron vs. Polygon — What's the Difference?

In geometry, a polyhedron (plural polyhedra or polyhedrons) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices. The word polyhedron comes from the Classical Greek πολύεδρον, as poly- (stem of πολύς, "many") + -hedron (form of ἕδρα, "base" or "seat").

In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed polygonal chain (or polygonal circuit). The bounded plane region, the bounding circuit, or the two together, may be called a polygon.

A solid bounded by polygons.

A plane figure with at least three straight sides and angles, and typically five or more.

(geometry) A solid figure with many flat faces and straight edges.

A closed plane figure bounded by three or more line segments.

(optics) A polyscope, or multiplying glass.

(geometry) A plane figure bounded by edges that are all straight lines.

A body or solid contained by many sides or planes.

(geometry) The boundary of such a figure.

A polyscope, or multiplying glass.

A figure comprising vertices and (not necessarily straight) edges, alternatingly.

A solid figure bounded by plane polygons or faces

(geometry) Such a figure and its interior, taken as a whole.

A plane figure having many angles, and consequently many sides; esp., one whose perimeter consists of more than four sides; any figure having many angles.

A closed plane figure bounded by straight sides