PHP Include Static Page

I am trying to include a portion of a static page within a WordPress page. I’ve downloaded a plugin that contains a line of PHP that includes the pages, yet I’m at a loss of where this line needs to be. I’m new to this sort of thing, so I am completely confused. I have no idea how to go about doing this. Where do I put my static pages? How do I include them into the WordPress pages? I’m fairly knowledged with regular PHP includes, but haven’t a clue of how to use them with WordPress. Any help whatsoever would be greatly appreciated!