# Angle Between Line and Plane

The angle between a line, **r**, and a plane, **π**, is the angle between **r** and its orthogonal projection onto **π**, **r'**.

The angle between a line and a plane is equal to the complementary acute angle that forms between the direction vector of the line and the normal vector of the plane.

If the line, **r**, and the plane, **π**, are perpendicular, the direction vector of the line and the normal vector of the plane have the same direction and therefore its components are proportional:

#### Examples

1. Determine the angle between the line and the plane .

2. Determine the angle between the line and the plane.

3. Determine the angle between the line and the plane: