def get_dot_product_2D(vector1_2D, vector2_2D):
    """
    Get the dot product of two 2D vectors.  Good for calculating angles.
    
    Args:
        vector1_2D (list): eg. [0,0] vector
        vector2_2D (list): eg. [0,0] vector
        
    Returns:
        float: The dot product between the two 2D vectors.
    """
    return (vector1_2D.x * vector2_2D.x) + (vector1_2D.y * vector2_2D.y)