5.1 surround setup in pro tools is different than the ITU, how should we place speake

[Rockman413]

Hi guys,
As we know, the 5.1 surround setup in pro tools is different than the ITU.
Which one is more for Film?
Should I place my speakers according to ITU(in a circle) or like the 5.1 surround pan in pro tools(in a rectangle)?


And for ITU, the front 3 speaker are quite close to each other, How about the Cinema speakers? Are close to each other like ITU, or they are actually like the one in PT--The left one is at the most left of the screen, right one at the most right of the screen.