If you've ever sat in math class and wondered "When will I ever use this stuff?", have we got a math problem for you. In 1966, mathematician Leo Moser posed this mathematical quandary: "what is the shape of the largest area in the plane that can be moved around a right-angled corner in a two-dimensional hallway of width 1?" If that sounds a little like the question you might ask when moving furniture, you're in good company—mathematicians refer to this as the "moving sofa problem." Unfortunately, it remains unsolved to this day. Wrap your mind around it in the video below.