Create a two-dimensional polygonal surface.

The corner points of the polygon are required to be on the same plane. If this is not the case, the surface must be constructed using smaller polygons that do lie in a common plane.

On the Construct tab, in the Create Surface group, click the  Polygon icon.
Tip: Press S,2 to use the shortcut key.

Corner 1 (C) The first corner of the polygon.
Corner 2 (C2) The second corner of the polygon.
...Corner n (Cn) Additional corners of the polygon (an arbitrary number). All must be in the same plane. The polygon is closed by connecting the last point to C1.