6. Find the value of each missing variable.

Answer:
x = 110
y = 102
z = 82
Step-by-step explanation:
Angles that create a line are equal to 180
x + 70 = 180
x = 110
y + 78 = 180
y = 102
A quadrilateral's angles add up to 360
110 + 78 + 90 + z = 360
278 + z = 360
z = 82