1024x576 are 16:9 Ratio
Warring: can break your monitor if set wrong!
$ cvt 1024 576
$ xrandr --newmode "1024x576_60.00" 56.00 1024 1064 1160 1296 576 579 584 599 -hsync +vsync
$ xrandr --addmode VGA-1 1024x576_60.00