Planar Surface
()
Keyboard: PLANESURF
Creates a planar surface.
Specify first corner or [Entity]: To create a rectangular planar surface, specify a point for the first corner, and then select the opposite corner. To convert an existing entity to a planar surface, choose Entity.
Select entities: Select closed, planar entities such as polylines, polygons, circles, ellipses, closed splines, and donuts, then press Enter. You can also select open entities such as lines and arcs, if they have common endpoints and they form a closed area.