But it _all_ triples?

> I sketch how the stereographic projection of the Stern–Brocot tree forms an ordered binary tree of Pythagorean triples, which can be used to compute best approximations of turn angles of points on the circle and finally trigonometric functions

The permutation and stack problem in the page seem to indicate this is a potential method for approximations, but insufficient for _all_

That said I am reading this on mobile and may have missed something.