各级各类学校在教学中往往要画图,而椭圆则是比较经常遇到的图形之一。不仅数学课中有椭圆,其他课也常有。如桶、杯、碗、球等有关圆的器具、物体,画其立体直观图,实际往往归结为画椭圆。相当多的企、事业单位也常要画椭圆。用几何课是所讲的方法画椭圆,可以画得很好,但太繁琐。有时许多辅助线纷繁交错,最后还要细致地擦掉。因此有关方面的许多人员迫切希望能够使用一种工具来画椭圆,而且能够类似于画圆那样既精确 Schools at all levels and types often draw pictures in teaching, and ellipses are one of the more frequently encountered figures. Not only are there ellipses in math classes, other classes are also common. Such as barrels, cups, bowls, balls and other round devices, objects, drawing their stereoscopic visual map, the actual is often attributed to the painting ellipse. Quite a number of enterprises and institutions also often draw ellipses. Using the geometry class to draw ellipses can be very good, but it is too cumbersome. Sometimes many auxiliary lines are intertwined, and in the end they must be carefully wiped off. So many people in the area are eager to be able to use a tool to draw ellipses and can be as precise as a circle