I was able to find a few pieces of information in a Garmin G1000 Manual.
10.4 inch diagonal display:
Overall height and width with bezel: 7.70" high x 11.80" wide.
Using a bit of math I was able to determine the screen viewing area with a 4:3 screen.
3 (screen height) 4 (screen width) 5 (screen diagonal) ratio numbers.
To find screen height with a 12" diagonal: 3 divided by 5 times the diagonal.
3/5 x 12 = 7.2" screen view height
To find screen width: 4 divided by 5 times the diagonal.
4/5 x 12 = 9.6" screen view width.
So, a 12" diagonal lcd has a screen display area of 7.2" h X 9.6" w.
Still could use some number on the actual G1000 bezel measurements.