Final answer:
In a quadrilateral inscribed in a circle, the opposite angles add up to 180 degrees.
Step-by-step explanation:
When a quadrilateral is inscribed in a circle, the opposite angles add up to 180 degrees.
Let's assume that angle GHI is x degrees and angle GIJ is y degrees.
Since angle H and angle J are opposite angles, they must add up to 180 degrees. So, angle H is 180 - x degrees. Similarly, angle I is 180 - y degrees.
So, the values of x and y are 180 - x and 180 - y, respectively.