The measurement of arc angle AC is (7x-2) degree. And measurement of angle ABC is (2.5x +4) degree.
And arc angle is twice of inscribed angle . So we will get

Distributing 2 on 2.5x and 4, we will get

Adding 2 to both sides and subtracting 5x, we will get

Dividing both sides by 2,

THerefore measurement of arc angle AC is
