Pipertommy,
To make the lift Bernoulli accelerated the airflow and coanda has thrown it downwards a little in response Newton has done the equal and opposite to us, The air behind the wing is a little lower than that in front so the blue line is the free stream air relative to us but the green is the air that we have influenced. The angular difference is the effect we have had on the air and that can be expressed as lift normal to the free stream and drag parallel to it.
