figure of eight polar diagram

例句：

1. 1.The scientist used a figure of eight to illustrate the relationship between the variables.
   科学家使用一个折线图来说明变量之间的关系。
2. 2. The engineer drew a figure of eight to show the path of the projectile.
   工程师画了一个折线图来表示弹道。
3. 3.The math teacher explained the concept of the figure of eight using geometric figures.
   数学老师用几何图形来解释折线八的概念。