We are asked to determine the arc length of HJ. To do that we will use the following formula:
Given two secant lines that intercept outside a circle as follows:
We have the following relationship:

Substituting the values we get:

Now, we multiply both sides by 2:

Now, we subtract 96 from both sides:

Solving the operations:

Now, we multiply both sides by -1:

Therefore, the measure of the arc length of HJ is 38.