I am using Sketchup Pro 2018.
This is a problem situation I seem to experience from time to time. The enclosed example has been maximally reduced to help illustrate the situation. Maybe anyone can explain why this occurs or if any tool or plugin can quickly remedy such a problem.
The actual problem here is the little triangle in the wall opening. If you select the triangle face, the the surrounding wall face is selected as well. This should imply that the triangle face is (at least) co-planar with the wall face, right?
Notice the two (blue) selected edges of the triangle. They are (as far as I can tell) actually CONNECTED to the window bottom edge. But if that were the case, clearly the triangle face should not be part of the rest of the wall face?
If the triangle edges were connected slightly ABOVE the window lower edge, the same should apply, the triangle face and the wall face should be distinct.
And if the triangle edges were connected slightly BELOW the window lower edge, then the two faces should also be distinct, because the triangle (actually it would then have four vertices) should be split in two by the window lower edge.
So it appears the faces are behaving as one single face, while in no case this should be so (given that the window lower edge is continuous, of course).
Is it just me being occasionally bugged by this type of phenomenon, or is this stuff bugging others as well? Anyone to explain why this is happening so?