Kekeya needle problem

Kekeya needle problem

[kā‚kē·ə ′nēd·əl ‚präb·ləm]
(mathematics)
The problem of finding the smallest area of a plane region in which a line segment of unit length can be continuously moved so that it returns to its original position after turning through 360°.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.