Some of the items like "File, Edit" are frequently used. But we may not need "Projects, Build, Tools, Help" unless we are dealing with code. If 909 is determined by the menus width, then the best resolution is probably to have the options of hiding some of these menu items.
Also, I checked ```geany.conf``` and ```geany.css``` and there does not seem to be a convenient way to resolve the problem. (Reducing the font size will prevent me from smoothly using "File", "Edit", etc.)