In given figure, AD is the bisector of BAC. Prove that AB > BD.
Given: In ABC, AD is bisector of BAC.
To prove: AB > BD
Proof: We know that
Exterior angle of triangle is greater than each of opposite interior angles then
In ADC
ADB > CAD (From above result)
Now, BAD = DAC (AD is bisector of BAC)
ADB > BAD
AB > BD (Since, side opposite to greater angle is longer)
Hence proved.