Angle Bisector

Definition of Angle Bisector

Angle Bisector is a ray that divides an angle into two equal parts.

More about Angle Bisector

  • Angle bisector is also called the internal angle bisector.
  • Angle bisectors of a triangle intersect at a point called incenter of the triangle.
  • A line or a line segment can also be an angle bisector at times. For example, the angle bisectors of polygons are line segments.

Examples of Angle Bisector

    In the example shown, OA is the angle bisector. It divides 60 into two equal parts (i.e. two 30's).
    exAngle Bisectorple of Angle Bisector

Video Examples: Angle Bisector - Geometry Help


Solved Example Clockple on Angle Bisector

Ques: In the given figure, is the angle bisector of ?AOB and is the angle bisector of ?COB. If m?AOC = 3y - 4 and m?COD = 28, then find the value of y.

    exAngle Bisectorple of Angle Bisector
    Choices:
    A. 56
    B. 28
    C. 20
    D. 112
    Correct Answer: C

Solution:

    Step 1: m?COD = 28, so m?BOC = 56, because is an angle bisector of ?COB.
    Step 2: m?BOC = 56 implies that m?AOC = 56, because bisects ?AOB.
    Step 3: So, 3y - 4 = 56 gives y = 20.