Three-bar truss ABC (see figure) is constructed of steel pipes having a cross-sectional area A = 3500 mm 2 and a modulus of elasticity E = 210 GPa. Member BC is of length L = 2.5 m, and the angle...

Three-bar truss ABC (see figure) is constructed of steel pipes having a cross-sectional area A = 3500 mm²
and a modulus of elasticity E = 210 GPa. Member BC is of length L = 2.5 m, and the angle between members A_C
and A_B
is known to be 608. Member AC length is b L = 0.71. Loads

P = 185 kN and 2P = 370 kN act vertically and horizontally at joint C, as shown. Joints A and B are pinned supports. (Use the law of sines and law of cosines to find missing dimensions and angles in the figure.)

(a) Find the support reactions at joints A and B. Use horizontal reaction B_x
as the redundant

(b) What is the maximum permissible value of load variable P if the allowable normal stress in each truss member is 150 MPa?