There's an old joke among mathematicians that topologists (who study deformations of space) can't tell a coffee cup from a donut. This is because, as far as the objects' topological properties are concerned, they're equivalent; they both have a single hole and can be deformed from one into another without tearing or gluing.
It turns out that the donut, called a 'torus' in topology, is a pretty basic surface, and there are a lot of other things besides coffee cups that can be made to transform into one if you use your imagination.
In the slideshow below, we investigated some other unlikely objects that are (more or less) topologically equivalent to a donut, from Rose McGowan's tube top to the 'A' guy in a 'YMCA' dance. See if you can imagine the transformations that would have to happen to make these objects into donuts, and add your own in the comments.