Take 10 golden triangles, arrange them with their sharp points touching, and you have a golden decagon, fitting perfectly within the iris of the eye, vertices neatly touching the rim.

画10个金三角，把它点挨着排好，然后你就得出一个金十形，与瞳孔中虹膜完美地一致，十形最早点正好在眼眶。