I got the files from the website listed, only improving them and adding new shapes.

The mathematician Leo Moser posed in 1966 the following curious mathematical problem: what is the shape of largest area in the plane that can be moved around a right-angled corner in a two-dimensional hallway of width 1? This question became known as the moving sofa problem and is still unsolved fifty years after it was first asked.

There is also a two-turned hallway that includes its own shape.

Here's a great video that shows it pretty well.