Interactive resource
Angle bisector property
Geometry. Points on the bisector are equidistant from the sides. Free interactive GeoGebra resource — adjust parameters in the browser.
Overview
Points on the bisector are equidistant from the sides.
Explanation
Any point on an angle bisector is equally far (perpendicular distance) from both sides.
Converse: points equidistant from the sides lie on a bisector (or its extension).
School “angle bisector theorem” about opposite-side ratios is a different statement.
How to use
Change the angle and slide P on the bisector; compare distances to the sides.