Answer:
D. x + y = w
Step-by-step explanation:
From the image, we observe that [tex]\angle X, \angle Y, \angle Z[/tex] are internal angles of the triangle.
So, they are internal angles then,
[tex]\angle X+ \angle Y+ \angle Z=180\°[/tex]
Now, from the image we observe that [tex]\angle w[/tex] is adjacent to [tex]\angle Z[/tex] and both must sum 180°, because they are on a straight angle, so
[tex]\angle w +\angle Z=180\°[/tex]
Then, we replace the second equation into the first one
[tex]\angle X +\angle Y +\angle Z=\angle w + \angle Z\\\angle X +\angle Y=\angle w[/tex]
Therfore, the right statement is D, because the sume of angles X and Y are equal to angle W.