Question

In a ΔABC, AD is the bisector of ∠A. If AB = 5.6 cm, AC = 4 cm and DC = 3 cm, find BC.

Answer 1

It is given that AD bisects ∠𝐴.
Applying angle – bisector theorem in Δ ABC, we get: 

`(BD)/(DC)=(AB)/(AC)` 

⟹`(BD)/3=5.6/4` 

⟹`BD=(5.6xx3)/4` 

⟹ BD=4.2 cm 

Hence, BC = 3+ 4.2 = 7.2 cm