Least-perimeter partitions of the disk into three regions of given areas Antonio CaneteManuel Ritore 49Q1051M2552A3852A40Isoperimetric partitionstabilitystable We prove that the unique least-perimeter way of partitioning the unit $2$-dimensional disk into three regions of prescribed areas is by means of the standard graph described in Figure 1. Indiana University Mathematics Journal 2004 text pdf 10.1512/iumj.2004.53.2489 10.1512/iumj.2004.53.2489 en Indiana Univ. Math. J. 53 (2004) 883 - 904 state-of-the-art mathematics http://iumj.org/access/