Answer:
Here,
X+50°=180°(being angle in a straight line)
or, X°= 180°- 50°
.°. X°= 130°
Again,
Y°+100°=180°( being co-interior angle)
or, Y°= 180°-100°
.°. Y°= 80°
Now,
Y°+Z°= 180°( being co-interior angle)
or, 80°+Z°= 180°
or, Z°=180°-80°
.°. Z°= 100°
Hope this helps you!