A-Best: The screen sizes are:
23.68 inches for a 37 inch TV;
25.6 inches for a 40 inch TV;
26.88 inches for a 42 inch TV.
There are two things you need to know about wide screen: The aspect ratio of a wide screen TV (which is 16:9) and that TV sizes are measured by a diagonal line across the opposite corners of the screen.
(Figures were calculated using the Pythagorean theorem and a simple ratio: [16 / 25] x screen size. Please correct me if I've made an error.)
Finally, just so we're clear about the "size of a bottom of a wide screen", the screen sizes are listed above; the TV's total size will vary based on manufacturer, existence of speakers in the model, and so on. I hope this helps!
