Found some free 1/4" tempered glass, HELP?!?

Hey guys, in a dilemma here... So i found 3 pieces of tempered glass today someone was throwing out and decided to pick them up thinking I found a treasure for my studio construction. Little did I know until 20min ago, tempered cannot be cut to the 3'x4' opening I cut in my double frame wall. -my walls are double frame wood stud w/ a 1" air space, and we'll have 2 layers of 1/2" gypsum on either side -so far, we've only put one layer on one of two frames and insulated between the frames Since my original intentions of grabbing the glass, cutting it to size and fitting it in my opening are now shot, I'm faced with this dilemma: do I go with a huge window and make my opening bigger, or do i just scrap the glass and buy it to size instead? The pieces I found are two identical 1/4" thick, 76" x 56" tempered safety glass, and another smaller 56" x 46" piece. Not sure what to do? ALSO, would 2 angled pieces of 1/4" tempered glass offer a higher STC rating than similar regular glass? i wasnt sure if tempered rated higher than regular. Thanks, I appreciate it! -andrew [removed]

Tempered glass can not be cut.

I'd get a cost comparison, see how ya feel with the free glass vs the other :)