Question taken from RD sharma
Class 10th
Chapter no. 4
Chapter name:- Triangles
Exercise :- 4.3
This is very basic and important questions.
In this question we have a ∆ABC, AD is the bisector of ∠A, meeting side BC at D.
Also sides measurements are given AB = 3.5 cm, AC = 4.2 cm and DC = 2.8 cm,
Now have to find BD
Understanding and learning CBSE maths
RD sharma, DHANPAT RAI publication
Given: Δ ABC and AD bisects ∠A, meeting side BC at D. And AB = 3.5 cm, AC = 4.2 cm, and DC = 2.8 cm.
Required to find: BD
Since, AD is the bisector of ∠ A meeting side BC at D in Δ ABC
⇒ AB/ AC = BD/ DC
3.5/ 4.2 = BD/ 2.8
4.2 x BD = 3.5 x 2.8
BD = 7/3
∴ BD = 2.3 cm