Since you haven't replied, I'll assume"broken" refers to the laptop's screen.
In that case you'll need to get the screen replaced or connect a standard 18"/18.5" widescreen external monitor to it.
Your laptop's GPU cannot cope with a 1080p monitor.
However, it's not going to be much good as a portable computer with a desktop monitor hanging off it! - - so I suggest you get the laptop's own screen fixed.