Multiple screens

So, I have a laptop with a 1920*1080 screen and I want to connect it with a 1680*1050 LCD monitor through VGA.

First make sure xorg-xrandr is installed:

# pacman -S xorg-xrandr

Connect the monitor and run:

$ xrandr -q

Note the names of the two outputs, then run:

$ xrandr --output LVDS1 --pos 0x0 --mode 1920x1080 --output VGA1 --mode 1680x1050 --left-of LVDS1