Connected Circles to Doval

Abstract

Doval is double closed curves which is defined as following. The ratio of two segments,that is to say,one is the distance between a fixed poit and the poit of curves, second is the distance between a fixed circle and the point of curves, is constant. Then the point of curves define an Oval as inner part and a colsed curve as outpart, This is Doval. Doval has a lot of circle which help to understand Doval Properties. For example auxiliary circles are used as one of deffinition of Doval. This time, we find two circles which is connected to Doval composition. And, we find the properties of those two circles. One is inside of inner part of Doval. Scond one is outside of outer part. WE find the motion of these circles, so it is reported using Cabri.