在初中阶段解一些代数应用题时,由于题意中的等量关系较为隐晦,若直接设置一个未知数,等量关系不是十分明晰,解题就会陷入困境,这时如果再设一些未知数,那么根据题意较易列出方程(组),再通过消元转化,使问题顺利获解,而增设的未知量可以不求,就可达到以简驭繁的解题效果.这种方法俗称“设而不求”.将“设而不求”解题思想迁移到求解(求证)几何问题,当某些几何题碰到无从下手时,类比地增设图中的某些角度或线段,用它们作为桥梁,建立方程(或函数)模型,把几何推理演变成 When solving some algebraic application questions in junior high school stage, because of the obscure relationship between the questions, if an unknown number is set directly, the equivalence relation is not very clear, and the solution will be in trouble. If some unknowns are set then According to the idea easier to list equations (groups), and then through the elimination of conversion, the problem was successfully solved, and the addition of unknowns can not ask, you can achieve the problem of Jane Yu Fan solution. This method is commonly known as “Set and not seek.” Move the idea of ​​solving the problem of “setting without asking” to the problem of solving (proofing) geometry. When certain geometry problems hit the wall, Line segments, using them as bridges, building equations (or functions), transforming geometric inferences into