\tan \theta = \frac{\sqrt{1 - \left(\frac13\right)^2}}{\frac13} = \frac{\sqrt{1 - \frac19}}{\frac13} = \frac{\sqrt{\frac89}}{\frac13} = \frac{\frac{2\sqrt2}3}{\frac13} = 2\sqrt2 - ToelettAPP