If mathematical theories can not be supported with physical examples, then they should be seriously questioned.
In OUR reality, 2 + 2 = 4 and it can be easily demonstrated by combining 4 physical objects.
And you are trying to do so on YOUR terms. I suggested a tool that might expand the terms you would be willing to use, but it is obvious from your posts that the only solutions you are entertaining are three-dimensional ones.
Here is another example. But we aren't able to make a scale model, or "picture" it in our minds.
You can easily picture a finite area that has no edge. Take a sphere, for example. A finite, limited two dimensional entity. The limited are of a sphere has no edge or boundary.
But, we can't readily imagine or picture a finite yet boundless volume. We tend to think of reality including an infinite space, with the universe expanding (or existing) at some location inside that space. And given a universe of finite volume and/or mass, we figure we could "get outside" the universe, into that empty space, and look back and see the universe.
But maybe, just maybe, it is not like that at all. Maybe "infinite empty space" does not exist. Even given a universe of finite volume and finite mass, perhaps the finite volume has no edge, no boundary, no "outside of the universe." Maybe space itself is finite! The notion boggles the mind, but it is exactly that notion that posters are attempting to express for your benefit.
Prove it, I can't. Heck, maybe I can't even express the notion well. But that's my best shot at it. Cheers. Ta Ta For Now.
But that method fails with: 10000000000000000000000000000000000000000000000000000000000000000000000000000000 000000000000000000000000000002 +10000000000000000000000000000000000000000000000000000000000000000000000000000000 000000000000000000000000000002.
Also, there is no physical example of numbers such as Sqrt(2) or Pi. Nor are there any isosceles triangles or right angles.