How I know my device screen ratio
To know your phone's aspect ratio and\or resolution there are many ways. One way is to go to this website and it'll immediately show you:
http://whatismyresolution.com/. If you'd like to know the ratio before buying any device you can simply ask about it. Most game developers intentionally develop games to adjust to any ratio the device is on, but some games aren't developed that way. This is most likely one of those games.. It really depends on your phone's screen size