Lisa Brock


Assignment 4

Proof that the Angle Bisectors of the Interior Angles of a Triangle are Concurrent



Prove that the angle bisectors of the interior angles of a triangle are concurrent.


Given Triangle ABC with angle bisectors AD, BE, and CF.



By the Angle Bisector Theorem,

, , 

By the Multiplication Property of Equality, 

By Algebra,

By Ceva’s Theorem, AD, BE, CF are concurrent.


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