you may have more luck if you attach the 3 borders separately- you could *easily-once you learn how* miter the inner narrow solid border- add the strip borders straight- then miter the outer wider solid border. mitering the pieced section may be a bit difficult. practice mitering with a couple pieces of scrap fabric to get the hang of it- once you get it you will find miters are really not difficult- it's just learning the process.