木工制作家具、门扇等活,常采用椭圆形图案。现介绍一种标准椭圆的简便画法。照图1那样,先把长轴A′A、短轴BB′的十字线交O点画出,就有了4个顶点A′、A、B和B′;以任一短轴顶点B或B′为圆心,长半轴 Woodworking furniture, doors and other activities, often using oval patterns. A simple drawing of a standard ellipse is introduced. As shown in Fig. 1, first draw the cross point of major axis A’A, minor axis BB’ to O, and then there are 4 vertices A’, A, B, and B’; with either short axis vertex B or B’ is the center of the circle, long axis