Screen wont strech on the entire monitor

[dudghks070505]

I want to play a game on a resolution (1080x1080) that is not the native resolution on the monitor (1920x1080), but when I do it, it does not stretch across the entire screen and it just has two black bars on the side. Does my monitor not support it or is there a way I can change it in the settings? I have a Samsung P2770H if that helps.

 

[drivinfast247]

Why do you want to play on that resolution?

 

[dudghks070505]

Why do you want to play on that resolution?

My friend plays on that resolution so I wanted to try it out. The game is Fortnite.