现在的工程技术人员大都能熟练地运用目前的教科书上教授的方法,放出图1所要求的IJKM的平面位置。但是,按照这一沿袭下来的习惯做法至少需要架设3次经纬仪,量取8段距离。众所周知,为了完成某一任务,可以有多种办法,人们总是要寻求那种在既定条件下既省时又省力的最优办法。那么,图1所给出的方法是否就是最优的办法呢? 让我们带着这个问题重新注意一下图1。可以看出图中CDIJ位于同一直线上。设想若能方便地求出IM的长度及其与直线IJ的夹角,那么只要确定了I点的位置,我们就可在I点架设经纬仪,用极坐标法方便地求得其余3点J、K、M的位置。事实上目 Today’s engineers and technicians can skillfully use the methods taught in current textbooks to release the planar position of the IJKM required by Figure 1. However, according to this customary practice, at least three theodolites need to be erected to measure 8 distances. As we all know, there are many ways to accomplish a certain task. People always look for the best way to save time and effort under the given conditions. So, is the method given in Figure 1 the best solution? Let’s take a look again at Figure 1 with this question. It can be seen that the CDIJ in the figure is on the same straight line. Imagine if we can easily find the length of IM and its angle with the straight line IJ, then as long as the location of I is determined, we can set up the theodolite at point I, and use the polar coordinate method to easily obtain the remaining 3 points J, K, M’s location. In fact