Answer: (17/90)π radian
Step-by-step explanation:
Arc length of AC = radius × angle APC
angle APC = Arc length of AC / radius
angle APC = ((68/15)π / 12) radian
angle APC = (17/45)π radian
Now,
2 × Angle ABC = Angle APC
Angle ABC = Angle APC / 2
Angle ABC = (17/45)π / 2
Angle ABC = (17/90)π radian
