Find the angle \(\varphi \)
between the line \(x + \sqrt{3}y - 6 = 0\)
and the line \(p\)
given by it's parametric equations.
\[
p\colon \begin{aligned}[t] x& = 2 + t,&
\\y& = 5,\ t\in \mathbb{R}
\\ \end{aligned}
\]
Given points \(A = [-1,4]\),
\(B = [2,-2]\) and
\(C = [5,-1]\), find the angle
\(\beta \) (the interior angle
at the vertex \(B\))
in the triangle \(ABC\).