Put three screens in portrait and never look back.
+-----+------------+-----+
| | | |
| | | |
| | | |
+-----+------------+-----+For those of you who don't know, the ratio of sides on A-series paper (A4, etc) is 1:sqrt(2), which means that if you put together 2 sheets of A4 with the long edges touching, you get the next size up, which would be A3.