[Wolves] vga monitor problem

[Mark Croft Redditch Linux Mint]

hi

i have been give a 22" HDMI &VGA  TV/monitor.

there a small fault at the bottom of the screen. Is there a way too
get linux mint/ubuntu based distro too not use that section of the
screen. find pictures attached.

seems to be something too do with this command - xrandr --fb 1160x568
--output VGA --mode 1280x800

but i am get a bit lost with it?

trying to follow this website (which usually pretty good)
http://superuser.com/questions/248840/limit-video-output-to-a-section-of-a-display-and-leave-the-rest-blank

https://www.facebook.com/media/set/?set=a.10154446564527049.1073741883.645232048&type=1&l=f98a97c3f0

not sure i can put image attachments or not?