平面几何难学,是很多初中生在学习中的共识,这里面包含很多主观和客观因素,而学习不得法,没有适当的解题思路则是其中的一个重要原因.波利亚曾说过:“解题的成功要靠正确思路的选择,要靠从可以接近它的方向去攻击堡垒.”为了辨别哪一条思路正确,哪一个方向可接近它,就要试探各种方向和思路.平面直角坐标系是联系数和形的一个重要工具,平面直角坐标系在研究方程、方程组、不等式、函数中有重要的作用.借助坐标 Plane geometry difficult to learn, is the consensus of many junior high school students in learning, which contains many subjective and objective factors, and learning is not law, without proper problem-solving ideas is one of the important reasons.Poria said: “The success of a problem depends on the choice of the right idea, and the attack on the stronghold from which it can be approached.” "In order to discern which line of thought is right and which one of the directions is close to it, test the various directions and ideas. Cartesian coordinate system is an important tool for the number and shape of contact, Cartesian coordinate system in the study of equations, equations, inequalities, functions have an important role.Using coordinates