Answer
Option B is correct.
Angle ABC = 68°
Step-by-step explanation
To answer this question, we need to first note that when a triangle has two sides that are equal in length (isoscelles triangle), the base angles of those two sides are often equal to each other.
We also need to note that the sum of angles in a triangle = 180°
And the sum of angles on a straight line = 180°
AB = AC
This means that
Angle ABC = Angle BCA
AC = CD
This means that
Angle CAD = Angle ADC
We are given that Angle ADC = 34°
Angle CAD = Angle ADC = 34° (Base angles of an isoscelles triangle are equal)
So, we can then find the third angle of triangle ACD
Angle ACD + Angle CAD + Angle ADC = 180° (Sum of angles in a triangle)
Angle ACD + 34° + 34° = 180°
Angle ACD + 68° = 180°
Angle ACD = 180° - 68° = 112°
Angle BCA + Angle ACD = 180° (Sum of angles on a straight line)
Angle BCA + 112° = 180°
Angle BCA = 180° - 112°
Angle BCA = 68°
Then, we can easily recall that
Angle ABC = Angle BCA (Base angles of an isoscelles triangle are equal)
Angle ABC = Angle BCA = 68°
Hope this Helps!!!