Unit vectors or direction vectors point to a given direction and have a magnitud of 1. if you scale them, they are no longer *unit* vectors ( no longer ortho**normal** ) because their magnitud is not equal to one and if you scale them uniformly their direction will change.

Dot Product *does not* scale vectors, it separates the magnitud from the direction. the result of the dot product is equal to the cosine of the angle between the two direction vectors.

For example: the dot product of these two unit vectors ( 1, 0 ) · (0.9659, 0.2588) = 0.9659 = ACOSD( 0.9659 ) = 15 degrees = COS( 15 )*i* + SIN( 15 )*j*.

If you rotate Yaw 15° from 0 (Forward vector = ( 1, 0, 0 ) ), your resulting forward vector would be (0.9659, 0.2588, 0 ).

If you multiply both ( 1, 0 ) and (0.9659, 0.2588) by 10 making them non unit vectors ( orthogonal and not ortho**normal** ) → ( 10, 0 ) ( 9.659, 2.588 ) and calculate the dot product, you’ll get 96.59. This proves that the dot product equals the product of their magnitudes multiplied by the cosine of the angle between them → 10 * 10 * cos( 15 ) = 96.59

This is a quick video I created for another topic about dot product: Dot - YouTube . The idea is the know the direction and difference in degrees from the forward direction of an actor (red arrow) to another actor by just using dot products.