A sector isoperimetric problem (Q2478011)

The author investigates and solves the problem of finding, in the Euclidean plane, the curve \(AB\) starting at a given point \(A\) and having a given length and such that the area of the sector obtained by joining the origin to the end points \(A\) and \(B\) is maximal. He shows that the optimal curve is a circular arc and he finds its center and radius. He also poses some open problems. Note that the special case when \(A=B\) is the classical isoperimetric problem. The paper is nicely written and is very pleasant to read.