Problem $4)(3$ points$)$ A consolidated drained triaxial test was performed on a normally consolidated clay, where the cell pressure was $1000$ psf $,$ and the deviatory stress at failure was $600$ psf $.$ a$)$ Find the drained internal friction angle and the failure plane angle to the horizontal for this clay $(1$ point$),$ b$)$ Find the effective normal stress and effective shear stress on the failure plane $(1$ point$),$ c$)$ Find the effective normal stress and effective shear stress on the plane of max. shear stress along with that plane's inclination angle to the horizontal $(1$ point$).$ Use the conceptual thinking with the help of a not$-$to$-$scale Mohr's circle drawing only $($like we did in the lecture $21).$ The use of any equation or scaling any value off the Mohr's circle will get no credit for this problem.