五角星形

例句：

1. 1. The pentagon is a geometric figure with five sides.
   五边形是一种有五个边的几何图形。
2. 2. The pentagram represents protection and infinity.
   五角星代表保护和无限。
3. 3. The pentagon was featured on the flag of the United States.
   五角星是美国国旗上的标志。