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,把它们的顶点挨着排好,然后你就得出一个金十边形,与瞳孔中的虹膜完美地一致,十边形的最早点正好在眼眶。
In geometry, a decagon is a ten-sided polygon or 10-gon.
A regular decagon has all sides of equal length and each internal angle will always be equal to 144°. Its Schläfli symbol is {10} and can also be constructed as a truncated pentagon, t{5}, a quasiregular decagon alternating two types of edges.