This article explains how to rotate a monitor's orientation with XRandR

XRandR is a utility used to configure displays in a Linux environment. XRandR can be used to adjust orientation, resolution and other settings.

Below are some commands to configure the orientation of a monitor with XRandR:

• $ xrandr -o inverted
  • Flips orientation
• $ xrandr -o left
  • Rotates orientation 90 degrees to the left
• $ xrandr -o right
  • Rotates orientation 90 degrees to the right
• $ xrandr -o normal
  • Returns the monitor to default orientation

See more commands at the XRAND on X.org