How many protons in the known universe

Originally posted by FabianFnas
I surely give a try but I don’t know if my definition about flatness is the right one, but it works for me. Here it goes...

If you draw a triangle, you know from the schooldays that the sum of triangles are exactly 180, right? That’s because you draw it on a flat surface.
If you draw it large enough, so large so you have to take the spherical form of ...[text shortened]... my thesis. Either it is wrong or it is right.
If anyone says the universe is flat, I just nod.

I heard also that it was possible for the universe to be flat and finite, and if this was the case the geometry of the universe would be donut-shaped. I assume that a triangle drawn on a donut-shaped curvature would give the same angle and area results as one on a flat surface.