What is the value of x?

enter image source here

1 Answer
Feb 5, 2017

x=3

Explanation:

enter image source here

Since CD bisects angleACB, by Angle bisector theorem, we know that:
(BD)/(AD)=(BC)/(AC)
=> x/2.25=4/3, => x=(2.25*4)/3=3

Alternative solution : using Sine Law
In DeltaACD, 2.25/sina=3/sinb ------------EQ(1)
In DeltaBCD, x/sina=4/sin(180-b)
As sinb=sin(180-b)
=> x/sina=4/sinb ------------------------EQ(2)

By dividing EQ(2) by EQ(1), we get:
x/2.25=4/3
=> x=(2.25*4)/3=3