decagon

常见例句

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.
畫10個金三角，把它們的頂點挨著排好，然後你就得出一個金十邊形，與瞳孔中的虹膜完美地一致，十邊形的最早點正好在眼眶。
how many diagonals are there is a decagon?????
一個十角形中有多少條對角線？
regular decagon
正十邊形