1. **Stating the problem:** Given that the measure of angle $X$ is 75 degrees and the measure of an exterior angle at $Z$ is 160 degrees, we want to find what is true about the values of $y$ and $z$. 2. **Understanding exterior angles:** An exterior angle of a triangle is equal to the sum of the two opposite interior angles. If the exterior angle at $Z$ is 160 degrees, then the interior angle at $Z$ plus the exterior angle at $Z$ must sum to 180 degrees because they form a linear pair. 3. **Calculate the interior angle at $Z$:** $$z = 180 - 160 = 20$$ 4. **Using the triangle angle sum property:** The sum of the interior angles of a triangle is always 180 degrees. So, $$X + y + z = 180$$ Substitute the known values: $$75 + y + 20 = 180$$ 5. **Solve for $y$:** $$y = 180 - 75 - 20 = 85$$ 6. **Conclusion:** The values are $y = 85$ degrees and $z = 20$ degrees.