Financial Projection Map Projection Map Projections Newman Projections Orthographic Projection Orthographic Projections Projection Vector Projections 14 Angle Addition Postulate 2 6 Practice Proving Angles Congruent 2 8b Angles Of Triangle 2 8b Angles Of Triangles 28b Angles Of Triangles 3 4 Angle Relationships 3 Types Of Angles 6th Grade Math There will generally be two angles between vectors an acute angle and an obtuse angle. in the dot product formula is the angle between two vectors that point in the same direction. So in this diagram the dot product formula will give you the blue obtuse angle.Honestly between the direction vector v(105-5) and the normal vector ( 2-14) the angle is not acute in fact it is obtuse (you can see that by a simple plot). However as you are asking about the angle between a line and a plane so the you must take care of the orientation of the vectors
It is necessary to use both dot and cross products to correctly resolve the angle. Angle between vectors u and v is atan2(sc) where s u X v (magnitude of the cross product) and c u.v (dot product) and atan2 is the 4-quadrant inverse tan function. and denotes magnitude (norm).The smaller angle is an Obtuse Angle but the larger angle is a Reflex Angle So when naming the angles make sure that you know which angle is being asked for
The scalar projection is equal to the length of the vector projection with a minus sign if the direction of the projection is opposite to the direction of b. The vector component or vector resolute of a perpendicular to b sometimes also called the vector rejection of a from b  is the orthogonal projection of a onto the plane (or in general hyperplane ) orthogonal to b .