Answer:
x = 13.6 cm or 16.0 cm, depends on where x sits.
Explanation:
The picture below shows my work. I was able to find all of the degrees for the angles, so I used trig functions to work it out.
One side is 8.5 cm
Another side is 13.6 cm
The longest side, which is the hypotenuse, is 16.04 cm, which is 16.0 cm rounded.
My work is below on the picture to show you how it is done. Sorry it is a little messy.