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.

10三角，把它们的顶挨着排好，然后你就得出一十边，与瞳孔中的虹膜完美地一致，十边的最早正好在眼眶。