text: It is irrelevant that the terminal ray is pointing whatever number.  tan(0) is just always 0.\n\nQuestion: Rewrite x in radian as quantity in degree.\nAnswer: We use the ratio pi(radian):180(degree).\nIf we let d be the quantity in degree for x in radian, we can find d from the following ratio equation.\n\nx(radian) : d(degree) = pi(radian) : 180(degree)\n=> (pi)d = 180(x)\n=> d = 180(x)/pi\n\nIn your question, x = 3pi/4.  Hence, d = 180(3pi/4)/pi = 135 (degree).