关键词: 多焦点圆, 椭圆, 卵圆, 环线, 焦点多边形, 组合曲线

Abstract: Ovals are familiar but not yet well-known basic graphics. To explore the
understanding for them the concept of multi-focus circle is put forward to explore the inherent
properties of the standard ellipse and ovals. Ellipses have two standard types, linear two focuses
and rhombus four focuses, and the oval is the specific fusiform four focus circle. Based on the
analysis, a special kind of parameter simulation method and some examples are given, which
deepens the basic understanding for ovals.

Key words: many focus round, oval, egg circle, loop, focus polygon, combination curve