25. Well, you’ve got me there! But, so what?
Glad you asked! You see, the basis of the BBS-ISL Matrix is that of the circle/square. Perfectly symmetrical geometric forms containing 90° right-angle isosceles triangles. These inform ST in a manner reflecting these properties.
Now, enter the PTs. PTs are based on 90° right-angle NON-isosceles triangles, i.e., when paired they form NON-square rectangles as opposed to the squares of the ISL. Such rectangles are longer than they are wide (bilateral symmetry).