几何画板在高等几何绘图中的应用

Utilization of Geometric sketchpad in Higher Geometry Drawing

笛沙格定理和帕斯卡定理是射影几何中的重要定理,根据这些定理的原理,可导出绘制平面与柱面锥面等直纹面的交线、绘制由平面上一些点或点与直线确定的二次曲线的方法。然而这些方法通过手工描绘仍难以实现,使用计算机则使问题变得简单。利用几何画板软件的轨迹功能,可以方便地进行柱面锥面的截线、曲线的投影和二次曲线的绘制。

Desargues theorem and Pascal theorem are important theorems in projective geometric.Based on principles of these theorems,methods of drawing intersection between straight grain surface such as plane and cylinder cone,and of drawing conic determined by points on the plane or by point and straight line can be derived.However,these methods remain hard to achieve through hand drawing,which will become easier by use of computer.By way of the track function in geometric sketchpad,drawing of sectional line on cylinder cone,curve projection and conic can be conveniently conducted.