$2.)$ The thin plate ABCD is subjected to a uniform loading such that the state of stress is constant throughout the solid.

a$.)$ Express the stress tensor in matrix form, $[].$

b$.)$ Determine the traction vector $($ stress vector$)$ acting on planes perpendicular to the page which pass through line segments CE and EF$.$

c$.)$ Determine the normal stresses and shear stresses on planes CE and EF$.$