A line $$AB$$ in three-dimensional space makes angles $${45^ \circ }$$ and $${120^ \circ }$$ with the positive $$x$$-axis and the positive $$y$$-axis respectively. If $$AB$$ makes an acute angle $$\theta $$ with the positive $$z$$-axis, then $$\theta $$ equals :
- A$${45^ \circ }$$
- B$${60^ \circ }$$
- C$${75^ \circ }$$
- D$${30^ \circ }$$
✓ Correct answer: B
Want the full step-by-step reasoning?