WXYZ is a parallelogram. Find the measure of angle Z

Given:
The figure of a parallelogram.
To find:
The measure of angle Z.
Solution:
We know that, the consecutive interior angles of a parallelogram are supplementary angles, it means there sum is 180 degrees.
In the given figure angle W and angle Z are supplementary angle. So,
[tex]m\angle W+m\angle Z=180^\circ[/tex]
[tex](18b-11)^\circ+(9b+2)^\circ=180^\circ[/tex]
[tex](27b-9)^\circ=180^\circ[/tex]
[tex](27b-9)=180[/tex]
Adding 9 on both sides, we get
[tex]27b=180+9[/tex]
[tex]27b=189[/tex]
[tex]b=\dfrac{189}{27}[/tex]
[tex]b=7[/tex]
Now,
[tex]m\angle Z=(9b+2)^\circ[/tex]
[tex]m\angle Z=(9(7)+2)^\circ[/tex]
[tex]m\angle Z=(63+2)^\circ[/tex]
[tex]m\angle Z=65^\circ[/tex]
Therefore, the correct option is C.