straight-line law

例句：

1. 1. The straight-line law states that the distance between two points on a line is equal to the sum of the lengths of the segments connecting those points.
   直线定律表明，两点之间的线段长度之和等于这两点之间的距离。
2. 2. In geometry, the straight-line law is used to describe the relationship between parallel lines and their corresponding segments.
   在几何学中，直线定律被用来描述平行线及其对应线段之间的关系。
3. 3. The straight-line law is often used in engineering calculations to determine the length of a straight linesegment.
   在工程计算中，直线定律常被用来确定一条直线段的长度。