Definition:Geometric Figure/Rectilineal Figure

Definition

In the words of Euclid:

Rectilineal figures are those which are contained by straight lines, trilateral figures being those contained by three, quadrilateral those contained by four, and multi-lateral those contained by more than four straight lines.

(The Elements: Book $\text{I}$: Definition $19$)

Also see

• Definition:Polygon: a plane rectilineal figure.

• Definition:Polyhedron: a three-dimensional rectilineal figure.