To determine the measure of arc GH, we first need to recognize that circles F and J being congruent means they have the same radius and, consequently, the same overall properties. This includes the measures of their arcs.
If we have any specific measure related to either circle, say the angle that subtends arc GH in circle F, we could apply it directly to circle J since the two circles are congruent.
For example, if angle GHF measures 40 degrees in circle F, then arc GH would also measure 40 degrees in circle J. In essence, the measure of arc GH depends on the angle subtending it at the center of circle F or circle J.
Therefore, to conclude, the measure of arc GH is equivalent to the measure of the angle that subtends it, in either of the congruent circles.