I think that you need to _construct_ the circle after you find its centre rather than _draw_ it . To do this, (1) draw a line through the center (intersection of the angle bisectors) which is perpendicular to one of the sides of the triangle. (2) construct a point at the intersection of the perpendicular and the side (3) construct a circle with center point at the angle bisectors' intersection and as the radius point use the point constructed in (2). This should give you the in-circle, which touches the triangle at 3 points.
Hakan Aras wrote:
> When I draw an inscribed circle in any triangle using the intersection point > of the angle bisectors as the center point of that circle, Cabri and > Sketchpad claim that they have no intersection point(s) although visually > the circle seems to touch the triangle at three points. When I enlarge the > circle a little, this time those sofware claim that it touches the triangle > at six points( two intersection points for each vertex).There is no other > case between these.As far as i know from my experiences. > But theoretically every inscribed circle is drawn by using the intersection > point of the angle bisectors as the center point of that circle. > So does it mean that these software are deficient to do this task?