Let \(\vec{a}, \vec{b}, \vec{c}\)be three coplanar concurrent vectors such that angles between any two of them is same. If the product of their magnitudes is 14 and \((\vec{a} \times \vec{b}) \cdot (\vec{b} \times \vec{c}) + (\vec{b} \times \vec{c}) \cdot (\vec{c} \times \vec{a}) + (\vec{c} \times \vec{a}) \cdot (\vec{a} \times \vec{b}) = 168\), then \(|\vec{a}| + |\vec{b}| + |\vec{c}|\)| is equal to :
Two lines:L₁: \(x = 5, \; \frac{y}{3 - \alpha} = \frac{z}{-2}\)L₂: \(x = \alpha, \; \frac{y}{-1} = \frac{z}{2 - \alpha}\)are coplanar. Then \(\alpha\) can take value(s):