Help u guys plssss number 8

Answer:
27
Step-by-step explanation:
Note : -
That square like symbol at the intersection of two lines is 90°.
( 4x - 18 )° and 90° are corresponding angles.
Corresponding angles are equal since lines
a & b are parallel.
4x - 18 = 90
4x = 90 + 18
4x = 108
x = 108 / 4
x = 27