+9491 Here's a graph you can play with: https://www.desmos.com/calculator/wy7dptwaij
To start with, both angles are set at 38° so both triangles are congruent (by SAS congruency).
Try changing the slider for b to make that angle bigger and see what happens to the length of YX
And note that the lengths of WX and WZ stay constant.
*edit*
Here is a new graph with calculation for the lengths of ZY and XY and a slider for the length of WY (in the folder):
