An octagon is a flat shape with eight straight sides and eight corners. The picture most learners know is a STOP sign — that red sign is an octagon on purpose, so you can still read the shape when snow or dirt covers the word.

An octagon octagon是is a flat shape一種平面形狀with eight straight sides有八條直邊and eight corners和八個角；The picture most learners know大多數學習者熟悉的畫面is is a STOP sign停止標誌— that red sign那個紅色標誌is an octagon on purpose故意做成八邊形, so這樣you can still read the shape你還是能認出形狀when snow or dirt covers the word即使雪或泥蓋住了字

You also meet octagons in maths class, in floor tiles, in some windows and tables, and in the floor of a fighting ring people call “the octagon”. That last use is a stretch: it is still the eight-sided shape, just used as a place-name.

You你also meet也會遇到octagons八邊形in maths class在數學課上, in floor tiles在地磚上, in some windows and tables在一些窗戶和桌子上, and in the floor of a fighting ring在拳擊或格鬥擂台的地板上people call人們稱之為'the octagon''the octagon'；That last use最後這個用法is a stretch算是延伸用法: it它is still仍然是the eight-sided shape那個八邊的形狀, just只是used as被用作a place-name一個地方的名稱

In careful talk, octagon is the noun (the shape itself). If you want a describing word in front of a noun, English usually wants octagonal.

In careful talk在講究的用法裡, octagon octagon是is the noun名詞（the shape itself指形狀本身）；If you want如果你想要a describing word一個形容詞in front of a noun放在名詞前面, English英文usually wants通常要用octagonaloctagonal