All of the angles add up to 360 degrees.
180(4-2) = 360
9x+1+5x-12+8x+61
Add up all the like terms
22x+50= 360
x=14.1
We are going to add up all of the angles together and subtract them by 360 in order to find the measurement of the missing angle.
Angle C: 9(14.1) + 1 = 127.9
Angle D: 5(14.1) - 12 = 58.5
Angle A: 8(14.1) + 61 = 173.8
All of these angles add up to 360
This means that angle D is 0 degrees since all of the other angles already add up to 360.
Answer
0 degrees