The two-bar truss ABC shown in has pin supports at points A and C, which are 2.0 m apart. Members AB and BC are steel bars, pin connected at joint B. The length of bar BC is 3.0 m. A sign weighing 5.4 kN is suspended from bar BC at points D and E, which are located 0.8 m and 0.4 m, respectively. from the ends of the bar. Determine the required cross-sectional area of bar AB and the required diameter of the pin at support C if the allowable stresses in tension and shear are 125 MPa and 45 MPa, respectively. (Note: The pins at the supports are in double shear. Also, disregard the weights of members AB and BC.) 2.0 m 0.8 m +0.9m+0.9m E 0.4 m W=5.4 kN