[cong-or]

Fair enough—I wasn’t imagining tiny compass-wielders. I was thinking more about whether the structure of a geometric construction might map to something computationally useful, like exact arithmetic systems (CGAL-style) that preserve geometric relationships and avoid floating-point degeneracies.

But for a constant like φ, you’re right—(1 + sqrt(5)) / 2 is trivial and stable. No clever construction needed.