Why does it matter to have width/height of the screen itself, when you already have the diagonal and aspect ratio?
I think a more useful metric would be the height/width size of the entire display, including the bezels. Otherwise, it's just redundant information to want to know the height/width of just the screen when you already have a feel for it based on the existing information.
But other missing information that is even more important: the pixel count - usually given in width x height in number of pixels.