For example, after reviewing the passage, we found that many times in the background of the college entrance examination, the knowledge of the circle is not only confined to the definition, that is, the distance from a fixed point in the plane to a fixed point is equal to the locus of a fixed point is a circle. But in the college entrance examination, the examination of the circle as the background knowledge does not stop at the definition, then we can sum up the path of the circle in which there are 13 ways, with the help of drawing software, the dynamic trajectory map sent to the wechat public platform, so that students at a glance, such as the Apponis Circle, Mongolian yen and so on.