(a) calculate the moment at point "c", where point "c" is the square 3'' below the centroid

(b) calculate the bending stress at the point "c" at 3 inches below the centroid

(c) given that the shear stress is 22.3 psi, draw a mohr's circle for the stress block

(d) prove the shear stress is 22.3 psi through calculating it