I am revising for a test which is next week. I came across this question and I keep getting the wrong answer. Someone please help! A particle has mass 2kg. It is attached at B to the end of two light inextensible strings AB and BC. When the particle is in equilibirum, AB makes an angle of 30 degrees with the vertical. The magnitude of the tension in BC is twice the magnitude of the tension in AB. Find, in degress to one decimal place, the size of the angle that BC makes with the vertical.