Geometry ?

I need to know the formula or process to do the following problems:

Find the missing parts required. Show all the work.

wz = 6, zx =8, wy = 9. Find xy. The figure that goes with this problem is a three sided out-of-shaped triangle. Help! I'm a Mom trying to homeschool and way over my head.

I'm sorry, but I have no idea what a " three sided out-of-shaped triangle" might be...? Also, are the letters variables, and these are equations, or are they points, and these are maybe side-lengths...? How do the letters relate to the picture you're looking at?

Thank you.

Eliz.