def _get_fitting_type(fitting_angle, rounded):
    """Returns fitting type for expansions and reductions.

    Parameters:
        fitting_angle: Fitting angle. Usually is 180 for square fittings.
        rounded: Rounded fitting. Usually is False for square fittings.
    """

    if fitting_angle != 180 and rounded:
        return 'ambiguous'
    elif rounded:
        return 'rounded'
    elif fitting_angle != 180:
        return 'tapered'
    else:
        return 'square'