How do you measure a TV's size?

Question

like this:

http://i2.photobucket.com/albums/y18/iamabug/fg/tv1.jpg

or like this:

http://i2.photobucket.com/albums/y18/iamabug/fg/tv2.jpg

Answer 1

diagonally

Answer 2

the advertised measurement is diagonally and only of the actual screen.

now if you are wanting to measure it for your cabinent/entertainment center, then you would measure the entire size of the tv, which includes the outer casing.