[ª] , [©] , [^] , [¨]Tracks of incenterEexcenter / Track of incenter(GC World : Various Problems ,Something strange?)
There is a circle O and the three corners of ĢABC are on the circle.
Please find the track of the incenter, when point A moves on the circle.

GC/Win


Forum of Geometric Constructor by Y.Iijima