10 answers
(click or scroll down)
This is messed up. I can only assume that Y is 20km away from X. Otherwise there is no way to figure anything out, since you give no other distances.
If you draw the diagram, you can easily see that angles
X=30°, Y=45°, Z=105°
If we label the sides opposite X,Y,Z as x,y,z then using the law of sines,
x/sin30° = y/sin45° = 20/sin105°