Finding direction angles for a vector

[brinlin]

 

[HOI]

Do you know what "direction angles" are? They are the angles the vector makes with each of the coordinate axes. The length of this vector is $\sqrt{2+ 4+ 2}=\sqrt{8}= 2\sqrt{2}$. That is the length of the hypotenuse of the right triangles the vector makes with each of the axes. The length of the side along the x-axis has length $\sqrt{2}$. The cosine of that angle is $\frac{\sqrt{2}}{2\sqrt{2}}= \frac{1}{2}$. So what is that angle?

Do the other angles the same way.