The angle of 90 degrees is for sure the most used angle when two flat faces in a construction have to be connected edge to edge. Looking around in the world of building we have to admit that this angle dominates. But when we look at the way this angle is used we have to conclude that in almost any case the result is just a box, a variation of the cube, compressed or stretched in one or two directions. Is this really all that is possible? Or can the use of this connection angle of 90 degrees lead to other shapes?