我们知道：研究曲线的位置关系的常用方法是代数法,即相应的方程组有无实根问题．直线与圆的位置关系还有几何法,即根据圆心与直线的距离与圆的半径的关系来判定直线与圆的位置关系．这里介绍一种判断曲线与有心二次曲线 (圆、椭圆、双曲线)位置关系的方法——三角法． We know that the common method for studying the positional relationship of curves is the algebraic method, that is, whether the corresponding equations have real root problems. The positional relationship between the straight line and the circle also has a geometric method, that is, the positional relationship between the straight line and the circle is determined based on the relationship between the distance between the center of the circle and the straight line and the radius of the circle. Here is a method to determine the positional relationship between curves and centered conics (circles, ellipses, hyperbolas)—triangulation.