Two identical specimens of soft, saturated, normally consolidated clay were consolidated to 150 kPa in a triaxial apparatus. One specimen was sheared under drained conditions, and the principal stress difference at failure was 300 kPa. The other specimen was sheared under undrained conditions, and the principal stress difference at failure was 200 kPa. Determine: (a) The effective stress friction angle, º
(b) The pore pressure at failure, uf