【摘要】 利用圆锥曲线的射影、仿射和度量性质的区分和三者之间的关系，论述了射影几何对中学解析几何教学的指导意义更多还原

【Abstract】 Projective property,affine property and metric property of circular curve and their relations are used in this paper.The influence projective geometry to elementary geometry is discussed.更多还原