Angle Bisector Theorem
Angle Bisector Theorem: Overview
This topic covers concepts, such as, Angle Bisector Theorem, Converse of Internal Angle Bisector Theorem,External Angle Bisector Theorem and Converse of External Angle Bisector Theorem etc.
Important Questions on Angle Bisector Theorem
In , is the bisector of that intersects BC in D. If and then find BD : DC?

In the adjoining figure if exterior , then is equal to:

In a triangle , the internal bisectors of meet at . Prove that is also internal bisector of .


The side of triangle is produced to .The bisector of angle meets in . Prove that .

In the figure, Point is on the side of such that and . Ray is the bisector of of . If is ,then find .

In what ratio of line divides the line segment joining and ?

In is the bisector of . Let units, units and units. Can you find the length of ( in units)

Amy drew a triangle on the board where is the line drawn on side , where, in, in, in and in. She wants to know whether is the angle bisector of . Can you help her?

State and prove the converse of angle bisector theorem

State the exterior angle bisector theorem.

is the bisector of the exterior meeting produced in . If and , find .

In the given fig. and is the bisector of . If and , then the value of will be

In the given figure, is the bisector of . If and . Find .

In , and. If bisector of meets at . Then is

and are the points on sides and , respectively of and intersect each other at T. If and , then

In triangle the point divides the extension of the line in the following ratio . Prove that the line is the bisector of the exterior angle .

The external angle bisector of a triangle divides the opposite side externally in the ratio of the sides containing the angle.


