Answer:
x = 6
Step-by-step explanation:
Using this theorem to get the other angles of the triangle.
Angle at the vertex is equal to half of the angle at the intercepted arc
For the arc with angle 170degrees
Angle at the vertex = 1/2 * 170
Angle at the vertex = 85 degrees
For the arc with angle 90degrees
Angle at the vertex = 1/2 * 90
Angle at the vertex = 45 degrees
Taking the sum of the 3 angles and equating to 180
85 + 45 + 12x - 22 = 180
130-22+12x = 180
12x = 180 - 108
12x = 72
x = 72/12
x = 6
Hence the value of x is 6