Squaring the circle is one of the most ancient problems of mathematics: given a circle, construct a square of equal area. This problem is closely related to the question of finding the value of pi, since for a circle of radius 1 has area equal to pi. Attempts to square the circle and find the value of pi go back as far as the oldest mathematical documents that have been discovered.

The earliest reference to the problem of squaring the circle is in the Rhind papyrus, an Egyptian document written about 1650 b.c., describing work that was performed 200 years earlier; some historians believe that it is based on work dating as far back as 3400 b.c.. The papyrus gives a technique for squaring the circle based on the assumption that pi is equal to 3.16. This is an excellent approximation, but it is not the exact...