How TO Cap Close Ellipse Polyline - create solid

Coming from AutoCAD background. I have LOFTed a few ellipses and a few closed polylines (half circle half rectangle), BUT need to have object as solid.
Naked edges show as leading ellipse and trailing polyline.
How do I cap the ellipse ?
How do I cap the half circle half rectangle closed polyline ?

Surprising there is a command called CAP, that will do that.