Okay so this is a problem I had back when I was designing a website, I gave up and used a different design but this problem has been bothering me ever since.

Let's say you have a rectangular shape, then the shape is skewed by some degrees (o) as shown in the picture. The top and bottom sides of the shape never change, the left and right sides do though. It feels like it should be possible to find the new length (z) using trigonometry, and I tried but quite frankly I'm retarded. I haven't been able to find any solutions online. Is this problem solavable?