import rhinoscriptsyntax as rs
allobj = rs.AllObjects()
rs.DeleteObjects(allobj)

#draw a closed curve in rhino
rs.Command("_Polyline 0,0,0 2.8,0,0 2.5,0,4.8 _Enter") 
crv=rs.FirstObject(select=True)


#points = [(0,0,0), (2.8,0,0), (2.5, 0, 4.8)]
#line = rs.AddPolyline(points)