Incircle and excircles of a triangle

Author:
Ian Barker
Triangle ABC and extended sides shown in red Internal angle bisectors shown in green External angle bisectors shown in blue Some construction lines and points are hidden
Incircle and excircles touch all three sides of ABC or their extensions Centres of the circles are at the intersections of three angle bisectors You can adjust positionof any of the vertices A, B C Note that the in circle is always smaller than any of the excircles