Definition:Angle Bisector/Internal

Definition

 * AngleBisector-Internal-External.png

Let $\angle APB$ be an angle.

The internal angle bisector of $\angle APB$ is the straight line which bisects $\angle APB$.

In the above diagram, $PC$ is the internal angle bisector of $\angle APB$.

Thus $\angle APC \cong \angle BPC$ and $\angle APC + \angle BPC = \angle APB$.

Also see

 * Definition:External Angle Bisector