It's also possible using a little trick without install other tools.
you have first to enable the embedded plug-in Python Console; you can find it in Edit --> Preference ---> Python Console (as you can see in the Picture)
then click on the bottom to the Python Console button ad you can resize your windows directly using the methods of the class window implemented in the Python Console (as you can see in the following picture):
In this example i resized the windows ( weight and height of 240px ) with the command:
window.resize(240,240)
where, from the help, the method needs two inputs:
resize(self, width:int, height:int)
There are a lot of other methods (e.g. window.fullscreen)
you can just use the command "help()" to show all methods of the class window:
help(window)