Calculate the.. half side?

Geometry Level 2

In Triangle ABC, an angle bisector AD is drawn to BC. If AB =6 , BD=4 AC=12, Calculate CD.

The answer is 8.

1 solution

Mehul Arora
Aug 3, 2015

Let CD=x

By Internal angle bisector theorem,

$\dfrac {6}{4}= \dfrac {12}{x}$

$x=CD=8$

I think this like proving the similarity of the triangles $ABD$ and $ACD$ , and then the ratio of the corresponding sides would be equal.

Sahba Hasan - 5 years, 10 months ago

That could be done too.

Mehul Arora - 5 years, 10 months ago

Right... u r in which class...10th? bcz u know about similarity of triangles....so that is y i asked.

Sahba Hasan - 5 years, 10 months ago

@Sahba Hasan – I'm in class 9

The favourite subject is math, and hence I know about it :)

Mehul Arora - 5 years, 10 months ago

@Mehul Arora – Can u tell me some sources from which u increase ur mathematical knowledge.? i too wan't to earn extra knowledge related to this subject

Sahba Hasan - 5 years, 10 months ago

@Sahba Hasan – Uhmm

Brilliant.org

Mehul Arora - 5 years, 10 months ago

@Mehul Arora – some more... i also use brilliant.org ;)

Sahba Hasan - 5 years, 10 months ago

@Sahba Hasan – That's all I do :)

Mehul Arora - 5 years, 10 months ago

Calculate the.. half side?

The answer is 8.

1 solution

0 pending reports