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That is a good question and is asked a lot by many people. I'll give a shot at answering it. Angle refers to the actual angle at which a point must be struck or manipulated to gain effect. Most of these are at 90, 45 or 30. This is the most overlooked component in getting desired reaction from the points. Some points can be struck at different angles to produce different effects. For example TW-17 must be struck at a 45 degree angle.
Direction is the direction of the force that is applied. For example TW-17 located behind the jaw and under the ear must be struck from the back of the head towards the front and slightly up.
Combining the two you get 45 degrees in toward the center of the head and from back to front.
This will give a KO in most cases especially when coupled with any of the other principles.
If I have not been clear, let me know.