TV screen sizes are measured on the diagonal. If you have a 27" tv (as I think I do) the 27" refers to the distance from the lower left corner of the tv to the upper right.
Old fashioned Cathode Ray Tube tvs have a 3/4 aspect ratio. This means that the height of the tv screen is 3 times a base number and the width is 4 times that number. For example, if I have a 27" screen, that makes the base number 5.4.
5.4 * 3 = 16.2
5.4 * 4 = 21.6
21.62 + 16.22 = 729
The Square Root of 729 = 27
When I get a new tv, I want the height of the screen to be at least as tall as the screen I currently have or 16.2" However, flat screen tvs have an aspect ratio of 9x16. The base number for a flat screen tv that is 16.2" tall is 1.8
1.8 * 9 = 16.2
1.8 * 16 = 28.8
28.82 + 16.22 = 1091.88
The Square Root of 1091.88 = 33.04361
This means that when I get a new tv, if I want to feel like I've gotten around the same size tv I'll need a 33" screen instead of a 27" screen. I'd like to get larger than that, but at least I have a baseline now.
And it helped! I'm able to concentrate a little more now.
I'm going to go get an analgesic though, that'll probably help even more.