If you want to extend a line or curve to form a face then it needs a ruby - unless you want to make a face and pushpull it up then erase the edges that are not needed to leave what you want - see Jean L's ideas... Didier has a script - see: http://www.crai.archi.fr/RubyLibraryDepot/Ruby/em_geo_page.htm extrudelines... Pick the edges and run the script - it makes the faces you want.