3 Verify that the point \(( - 1,6,5 )\) lies on both the lines $$\mathbf { r } = \left( \begin{array} { l } 1
2
1 \end{array} \right) + \lambda \left( \begin{array} { l } 1
2
3 \end{array} \right) \quad \text { and } \quad \mathbf { r } = \left( \begin{array} { l } 0
6
3 \end{array} \right) + \mu \left( \begin{array} { l } 1
0
2 \end{array} \right)$$ Find the acute angle between the lines.