A shaft with an equilateral triangular cross$-$section, where one side measures $75$ mm$,$ is subjected to torque at end B$.$ The safe torsional stress value for the shaft material is $60$ MPa, and the twist angle at B is $3$ degrees. The shear modulus of the shaft material is $26$ GPa. Calculate the torque that can be applied to the shaft and specify the preferred value for the system.