Answer:
D. x + y = w
Explanation:
From the image, we observe that
are internal angles of the triangle.
So, they are internal angles then,

Now, from the image we observe that
is adjacent to
and both must sum 180°, because they are on a straight angle, so

Then, we replace the second equation into the first one

Therfore, the right statement is D, because the sume of angles X and Y are equal to angle W.