Just saying, how pass fail is that. You either cut it correctly or you need another thing of glass. Long story short I changed a very broken window in my house for a slightly broken window, that I cut and kinda glued the bits back on. And only really had the one large enough piece of scrap glass. My mistake was using the glass cutter after I broke it. I fixed it with a pin, a nail, and a screwdriver, but it didn't cut the same (I cut a bunch of smaller bits of scrap glass to practice).