Incircle and Excircles

Author:
Terry Tam
For triangle ABC, I is the incenter, and the corresponding circle inscribed by the triangle is the incircle. JA, JB, JC are the excenters, and the corresponding circles tangent to the triangle sides/sidelines are the excircles. The sides of triangle JAJBJC (excentral triangle) are passing through A, B and C.