Answer:
x = 12
Step-by-step explanation:
The sum of exterior angles is = 360
one of the angle is given we will need to add all three angles
128 + 8x + 11x + 4 = 360 add like terms
19x + 132 = 360 subtract 132 from both sides
19x = 268 divide both sides by 19
x = 12 replace x in required expressions to find the measure of the angles
