But it is related to text that precedes my quote:
> One of the problems the two friends looked at was a version of a century-old unsolved question in geometry.
> “The problem is so easy to state and so easy to understand, but it’s really hard,” said Elizabeth Denne of Washington and Lee University.
> It starts with a closed loop — any kind of curvy path that ends where it starts. The problem Greene and Lobb worked on predicts, basically, that every such path contains sets of four points that form the vertices of rectangles of any desired proportion.
Emphasis mine. The article explicitly describes the problem they solved, only to later point out that they actually solved a different problem.