You resovle verticallly to find the tension in AB since using either cos/sin angle of tension will equal to the weight,then resovle horizontally to find tension BC then resovle horizontally again to find the missing angle
You resovle verticallly to find the tension in AB since using either cos/sin angle of tension will equal to the weight,then resovle horizontally to find tension BC then resovle horizontally again to find the missing angle