The (interior) bisector of an Angle is the Line or Line Segment which cuts it into two equal Angles on the same ``side'' as the Angle.

The length of the bisector of Angle in the above Triangle
is given by

where and . The angle bisectors meet at the Incenter , which has Trilinear Coordinates 1:1:1.

**References**

Coxeter, H. S. M. and Greitzer, S. L. *Geometry Revisited.* Washington, DC: Math. Assoc. Amer., pp. 9-10, 1967.

Dixon, R. *Mathographics.* New York: Dover, p. 19, 1991.

Mackay, J. S. ``Properties Concerned with the Angular Bisectors of a Triangle.'' *Proc. Edinburgh Math. Soc.* **13**, 37-102, 1895.

© 1996-9

1999-05-25