Mass−radius relationship for the sample stars. See Fig. 1 for the symbol encoding. Abscissa values are evolutionary masses. In addition to the ZAMS, two additional loci, for 50% core-H depletion and for the TAMS, are indicated by the thick/thin-dotted lines, as predicted by the stellar evolution models of Ekström et al. (2012). Error bars are shown also for the detached eclipsing binary components.