Step 1 :\(Q(-3,6)\) is on the terminal arm of angle \(\theta\) in standard position.
Step 2 :Calculate the distance from the origin to point \(Q\) using the distance formula: \(d = \sqrt{(-3)^2 + 6^2}\)
Step 3 :\(d = \sqrt{9 + 36} = \sqrt{45} = 3\sqrt{5}\)
Step 4 :\(\sin \theta = \frac{6}{3\sqrt{5}} = \frac{2}{\sqrt{5}} = \frac{2\sqrt{5}}{5}\)
Step 5 :\(\cos \theta = \frac{-3}{3\sqrt{5}} = \frac{-1}{\sqrt{5}} = \frac{-\sqrt{5}}{5}\)
Step 6 :\(\tan \theta = \frac{\sin \theta}{\cos \theta} = \frac{\frac{2\sqrt{5}}{5}}{\frac{-\sqrt{5}}{5}} = -2\)
Step 7 :\(\theta = \arctan(-2)\) in Quadrant II
Step 8 :\(\theta = \boxed{180^\circ - \arctan(2)}\)