def find_intercept_point(m, c, x0, y0):
    """ find an intercept point of the line model with
        a normal from point (x0,y0) to it
    :param m slope of the line model
    :param c y-intercept of the line model
    :param x0 point's x coordinate
    :param y0 point's y coordinate
    :return intercept point
    """

    # intersection point with the model
    x = (x0 + m * y0 - m * c) / (1 + m**2)
    y = (m * x0 + (m**2) * y0 - (m**2) * c) / (1 + m**2) + c

    return x, y