[ª] , [©] , [^]
, [¨]Tracks of incenterEexcenter / Excenter are three.(GC World : Various Problems ,Something strange?)
There is a circle O and three corners of ¢ABC are on the circle.
Three excenters are named I1, I2, and I3 respectively.
Please find the tracks of I1, I2, I3, when point A moves on the circle.