Answer:
30 degrees
Explanation:
Because the figure was dilated, the angle measures haven't changed, so the angle measures of XYZ should be the same as the angle measures of ABC. Using this fact and the fact that the angles of a triangle added up is always 180 degrees, we can set up an equation and solve.
Angle measure A + Angle measure B + Angle measure Z = 180
50+100+ Angle measure Z = 180
150 + Angle measure Z = 180
Angle measure Z = 30