八边形

例句：

1. 1. The shape of the octagon is very interesting.
   这个八边形的形状很有趣。
2. 2. Octagons are often used in architectural designs to create a sense of balance.
   八边形在建筑设计中经常被用来创造平衡感。
3. 3. In mathematics, an octagon can be defined as a polygon with eight sides.
   在数学中，八边形可以定义为一个有八个边的多边形。