relative length closing error of traverse

例句：

1. 1.The relative length of the two pieces of wood is 2 meters.
   这两段木头的相对长度是2米。
2. 2. The relative lengths of the two sides of a triangle are equal.
   三角形的两个边长之比相等。
3. 3.The relative lengths of the two sides of the triangle can be used to calculate the area.
   三角形两边的长度之比可以用来计算面积。