A few days ago I started to learn Altium Designer 17 and immediately stumbled upon some strange behavior. I created my first component and decided to see how it will look on paper. So I added this component to a schematic sheet, set the sheet size to A4 (look at the screenshot below), tried to print it, and... got not what I expected.
I began to look for the causes and noticed that the sheet on my screen has the wrong proportions! Approximately 0.66 instead of 0.707 for A4. When I ticked "Use Custom Style" and set all the sizes manually, the problem was solved. Okay, that's good, but why the standard style called A4 doesn't work? I tried to do the same thing in Altium 18 and got the same result.
It is interesting that in the "Tools->Schematic Preferences" dialog you can set the default sheet size. If you set this size to A4, the parameter called "Drawing Area" becomes equal to 292x193mm, which gives us this weird 0.66 ratio. So... This is not a bug. But what is it?
To make it more clear I made a screenshot. Here is my schematic sheet. In the document settings, the size of the sheet is set to A4 (see the first picture in my question). According to the standard, A4 has 0.707 height/width ratio, but neither A/B nor D/C equal to 0.707!