Unfortunately, this problem apparently comes without a diagram (or you have not shared the diagram that came with it). I'd strongly suggest either finding and posting the diagram or sketching your own diagram. Then we could refer to the rectangle more meaningfully (more specifically). Next, please identify what it is that you need to know to get started.
To be frank, your post looks like an explanation of a rectangle problem; you don't appear to be asking a question except for the one place where there's a blank that you're supposed to fill in.