I just installed FreeCAD under Ubuntu 18.04 from Ubuntu Software. In Ubuntu Software, I can click the Launch button to launch FreeCAD. But when I try to start FreeCAD from a terminal or from the start menu, it's nowhere to be found.
Where is the main program to start FreeCAD located?
You can start it via
/usr/bin/freecad
. However, that's just a symlink to the actual binary:/usr/lib/freecad/bin/FreeCAD
Edit: the above assumed that you installed it as a .deb package. You've installed a .snap package version which will have a different directory structure. http://www.linuxandubuntu.com/home/snap-vs-deb-package has more information about snap package directory structure.