Answer:
30 degrees
Explanation:
The computation of the value of x is given below:
Given that
ADC = 120 degrees
So ABC = 60 degrees
As the sum of the opposite angles are 180 degrees
And ACB = 90 degrees
Now in Triangle ADC
Angle ACB + Angle ABC + x = 180 degrees
90 + 60 + x = 180
x = 30 degrees