You may run into a Chromebook where a student has accidentally (or cleverly) rotated the screen. A rotated screen may look like this...
or like this...
Fortunately, this is an easy fix. You can toggle the rotation of the Chromebook screen using the key combination of:
Ctrl + Shift + Refresh
This combination will rotate the screen 90 degrees clockwise. Keep pressing the combination until the screen is correct for best use. If you still experience trouble, try to restart the device. If that does not resolve the issue,