angle bisectors


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).

Solved Example on Angle Bisector

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.

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°.

Related Terms for Angle Bisector

  • Angle
  • Bisector
  • Ray