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:
