concentric quadrics

例句：

1. 1.The shape of the quadrilateral is concentric to the circle.
   这个四边形的形状与圆同心。
2. 2. The concentric quadrics are used to create a smooth surface.
   这些同心四边形被用来创造一个平滑的表面。
3. 3.The concentric quadrics were used in ancient times to measure distances.
   这些同心四边形在古代被用来测量距离。