Answer
$52,0^\circ$
Work Step by Step
1. Use the given vectors, we have $\vec v\cdot\vec w=(3)(6)+(-4)(-8)+(1)(2)=52$
2. The angle between the vectors $\theta=cos^{-1}(\frac{\vec v\cdot\vec w}{||\vec v||||\vec w||})=cos^{-1}(\frac{52}{\sqrt {9+16+1}\sqrt {36+64+4}})=cos^{-1}(1)=0^\circ$
