Final answer:
To find the value of m in triangle XYZ, set the exterior angle equal to the sum of the remote interior angles and solve the equation.
Step-by-step explanation:
In triangle XYZ, the measure of angle Z is represented by (5m - 16), and the measure of its exterior angle is represented by (3m + 12). To determine the value of m, we set the measure of the exterior angle equal to the sum of the measures of the remote interior angles according to the Exterior Angle Theorem.
So, we have (5m - 16) + (3m + 12) = 180.
Solving this equation will give us the value of m.
Learn more about Triangle angles