Angle Bisector of a Plane Angle

Theorem: Angle Bisector of a Plane Angle

Let \(\angle(a;b)\) be the [[Plane Angle]] formed by two [[Rays]] \(a\) and \(b\).

There exists one and only one [[Straight Line]] \(l\) in the [[Planes|plane]] of \(\angle(a;b)\) which goes through the [[Plane Angle|vertex]] of \(\angle(a;b)\) such that the angles \(\angle(a; l)\) and \(\angle (l; b)\) are [[Geometric Shapes|congruent]].

Proof

TODO