If $\underline{a} = -10\underline{i} + 2\underline{j} + 4\underline{k}$ and $\underline{b} = \underline{i} - \underline{j} + 2\underline{k}$ then find a unit vector orthogonal to $\underline{a} \times \underline{b}$. Also find angle between the vectors $\underline{a}$ and $\underline{b}$.