Answer:
106
Step-by-step explanation:
If you find the sum of the interior angles, you can determine the supplement to z.
Then all you have to do to get z is to subtract it from 180.
Method
The supplement of 72 is 180 - 72 = 108
The supplement of 51 is 180 - 51 = 129
The supplement of 60 is 180 - 60 = 120
The supplement of 71 is 180 - 71 = 109
Let y = the supplement of z
y + 108 + 129 + 120 + 109 = 540
y + 466 = 540
y = 540 - 466
y = 74
z + y = 180
z + 74 = 180
z = 180 - 74
z = 106
I hope that get's rid of your headache.
