Angle θ between a Line having direction ratio vector \(\vec{A}\) and a Plane having normal vector \(\vec{B}\) is be given by the following formula

\(\theta = \sin^{-1} (\frac{\vec{A}\cdot\vec{B}}{\vert \vec{A} \vert \vert \vec{B} \vert})\)

The angle between the line and the plane can be given by θ or -θ. Generally positive values of angle are considered.