def to_dd(degrees, minutes, seconds=0):
    """Convert degrees, minutes and optionally seconds to decimal angle.

    Args:
        degrees (float): Number of degrees
        minutes (float): Number of minutes
        seconds (float): Number of seconds

    Returns:
        float: Angle converted to decimal degrees
    """
    sign = -1 if any(i < 0 for i in (degrees, minutes, seconds)) else 1
    return sign * (abs(degrees) + abs(minutes) / 60 + abs(seconds) / 3600)