You can use the tool Devilspie:
sudo apt-get update && sudo apt-get install devilspie
Devilspie is a non-gui utility that lets you make applications start in
specified workplaces, in specified sizes and placements, minimized or
maximized and much more based on simple config files.
Create a Devilspie configuration directory for the current user and then create a configuration file for devilspie, for example for gnome-terminal:
mkdir ~/.devilspie && echo gedit ~/.devilspie/gnome-terminal.ds
Add a desired contents, for example:
(if (is (application_name) "Terminal")
(begin
(geometry "800x400")
(center)
)
)
Now the command
devilspie
will execute the script and all open Terminal windows will be resized and positioned as in the script.
If you want these settings to be there by default, just add the "devilspie" command into your Startup Applications (search for Startup Applications in the Cinnamon main menu):
