The aluminum strut is fixed between the two walls at A and B. If it has a 2 in. by 2 in. s...

The aluminum strut is fixed between the two walls at A and B. If it has a 2 in. by 2 in. square cross section, and it is subjected to the torque of 80 lb • ft at C, determine the reactions at the fixed supports. Also, what is the angle of twist at C? Gal = 3.8(103) ksi.