Why do we check for square?
Let's say I'm installing a window. I put the window in the rough
opening, shim it up and grab my level.
It's plumb on both sides, and the top and bottom are level.
How could it *not*
For it to be out of square, at least 1 of the 4 readings I took with
my level would be off.
If the window were racked, then the sides wouldn't be plumb.
If one side was longer than the other, then the top wouldn't be level.
If the bottom was longer than the top, then one of the sides wouldn't
I can't think of a scenario where both sides are plumb and the top and
bottom are level but the window isn't square.
What's the point in checking for square?