The angle of attack is the angle between the chord line of an airfoil (such as a wing) and the relative wind. It’s crucial in aerodynamics because it affects lift and drag forces on an aircraft.
In the context of aerodynamics, the “opposite” side refers to the difference in height between the wing’s leading edge and trailing edge, and the “adjacent” side refers to the horizontal distance from the leading edge to the trailing edge along the chord line of the wing.