题13.两直角刚杆AC.CB支承如图,在铰C处受力F作用,则B处约束力与x轴正向所成的夹角为()


题13.两直角刚杆AC.CB支承如图,在铰C处受力F作用,则B处约束力与x轴正向所成的夹角为()

A.0°

B.45°

C.135°

D.180°

正确答案:C