Aldous huxley's novel brave new world and george orwell's 1984 are narratives about societies degenerating under totalitarian governments which catergory of science fiction best describes these novels?

The novels _Brave New World_ by Aldous Huxley and _1984_ by George Orwell are stories that take place within societies that are in a horrible state because of harsh governments and how, like the question notes, societies have degenerated because of totalitarian governments.  Things within these types of stories are the furthest from what one would consider “perfect” or “utopian.” Things are, thus, considered a “dystopia,” which is the antithesis of a perfect society.  As such, stories that fall into this category are termed “dystopian fiction.”

right angles are formed by perpendicular lines. if the lines would extend, to make two intersecting lines, they would form four right angles.