Q8 of 56 Page 6

The bisector of interior angle A of a triangle AB meets BC in D and the bisector of exterior angle A meets BC produced in E. Prove that
                                        

Given: ΔABC, AD bisects interior ∠A and AE bisects exterior ∠A meeting BC at D and BC produced at E.
To prove: 
Proof: In ΔABC, AD bisects interior ∠A
∴ (Angle Bisector theorem)…………………(1)
Similarly in DABC, AE bisects exterior ∠A
∴ ………………..(2)
From equation (1) and (2),
   
Hence Proved.

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