Answer Happy

Using the information from 1 could I please have the working and
solution for equation 2. Thanks
Q1 An over consolidated clay deposit has an undrained shear strength equal to 92.9 kN/m2. From drained test values of c and are found to be 28.8 kPa and 34.6 degrees, respectively. You can use either formulation or graphical method. If failure occurs in either the undrained state or drained state, what is the major effective principal stress at failure in kPa? Answer: 215.00 Check Q2 If failure occurs in the undrained state, what is the minor effective principal stress at failure in kPa? Answer: Check