Nonconvex Cases for Carpenter's Rulers

We consider the carpenter’s ruler folding problem in the plane, i.e., finding a minimum area shape with diameter 1 that accommodates foldings of any ruler whose longest link has length 1. An upper bound of 0.614 and a lower bound of 0.476 are known for convex cases. We generalize the problem to simple nonconvex cases: we improve the upper bound to 0.583 and establish the first lower bound of 0.073.