Final answer:
In a triangle, the largest angle is always opposite the longest side. Therefore, angle ZA is the angle with the greatest measure.
Step-by-step explanation:
In a triangle, the largest angle is always opposite the longest side. Using the given side lengths BC = 9, AB = 7, and AC = 13, we can conclude that AC is the longest side. Therefore, angle ZA is the angle with the greatest measure.
Learn more about angles in triangles