By Team Aakash Byju's | 8th December 2022

D Is a Point on the Side BC of a △ABC Such That AD Bisects △BAC. Then

BD > BA

BA > BD

BA = BD

BD = CD

A

C

B

D

Detailed Explanation

The correct answer is option  B)  BA > BD.

Arrow

The visualisation of the given case is shown below:

Since the line AD bisects ∠BAC, it is called the angular bisector of △ABC.

∴ ∠BAD = ∠CAD

We know that the external angle of a triangle is the sum of the opposite internal angles. So, in △ADC

∠ADB = ∠ACD + ∠CAD

=> ∠ADB > ∠ACD or ∠ADB > ∠CAD

So we know that ∠BAD = ∠CAD, and ∠ADB > ∠CAD. Thus, we can write:

∠ADB > ∠BAD

Therefore, in △ABD, ∠ADB > ∠BAD. Also, we know that, in a triangle, the greater angle has the longer side opposite to it.

The side opposite ∠ADB is BA

The side opposite ∠BAD is BD

Thus, ∠ADB > ∠BAD => BA > BD