江苏省高考中把圆和直线位置关系列为C级要求,这就说明直线和圆的重要性。直线和圆的位置关系中,相切又是最重要的关系,众所周知,在圆上的点可以作一条直线与该圆相切,过圆外一点可以作二条直线与该圆相切。在此我就圆的切线结论加以分析并利用其解决一些试题,供同学们参考。 Jiangsu Provincial Entrance Examination in the circular and linear position as a C-level requirements, which shows the importance of straight lines and circles. Tangent is the most important relationship between the straight line and the circle. As we all know, a point on a circle can be tangent to the circle. A point outside the circle can be tangent to the circle. Here I analyze the round tangential conclusions and use it to solve some questions for the students reference.