The K200D doesn't have live-view, it was introduced when that was still not a standard feature. You can't use the screen to frame your shots, only the viewfinder.
The camera does have a preview mode, this is customised in the menu to either depth-of-field preview or a preview of the shot. The latter takes a shot and shows it on the screen, and if you like it you have the option to save the preview. This is a bit silly as you're as well just taking the shot normally.
I will add that, although out-dated, the K200D is a great camera and is very enjoyable to use. I'm still using mine after four years and I have no plans to change. There's a fan thread here:
https://www.pentaxforums.com/forums/pentax-dslr-discussion/129204-anyone-else-miss-k200d.html.