25-Jun-1995
## Unsolved Problem 26:

##
Given a simple closed curve in the plane, can we always
find four points on this curve that are the
vertices of a square?

## Reference:

- [Croft 1991]
- Hallard T. Croft, Kenneth J. Falconer, and Richard K. Guy,
Unsolved Problems in Geometry.
Springer-Verlag. New York: 1991.
Page 51.

Inscribing a Square in a Curve

Each week, for your edification, we publish a well-known
unsolved mathematics problem. These postings are intended
to inform you of some of the difficult, yet
interesting, problems that mathematicians
are investigating. We do not suggest that you tackle these problems,
since mathematicians have been unsuccessfully working on these
problems for many years.
general references

previous problem

problem archive

next problem

electronic publications