follow the bellow link https://blogs.windows.com/buildingapps/2015/09/01/make-your-app-look-great-on-any-size-screen-or-window-10-by-10/

Please go through this below link and more information herehttps://docs.microsoft.com/en-us/xamarin/xamarin-forms/user-interface/images?tabs=windows

BY using the tag of On Platform