What is the largest sofa that you can squeeze around the corner of a hallway? A horseshoe-shaped piece of furniture known as Gerver’s sofa has officially taken the crown, solving a mathematical question first put forward almost 60 years ago.

The difficulties of getting large furniture into your home will be familiar to many people, but mathematicians have taken a particular interest in the moving sofa problem ever since it was first posed by Leo Moser in 1966. It supposes that you are trying to navigate a two-dimensional sofa (so ignoring…