So, what to do.. You have a couple of options..
You could trim it to fit.. but that is not the best solution, in my opinion..
Here is what I did.. I went back to my machine and resewed the seams with a fill quarter inch..you dont need to rip, as you are increasing the size of the seam...
I did one seam at a time, switching sides so that everything stays semetrical..when I got it the right size, I was done..
I had to do four seams to get it the right size..
You can use your pattern for the quarter circle to test it for size