If a girl asks this question, it is because most girls in the constellation prefer to study this. In particular, the analysis of a person's personality by constellations is sometimes accurate, so it depends on whether you care too much about trusting him.
It shows that this girl still believes in constellations, and she wants to know your specific personality through constellations. In this way, we can judge whether it is appropriate to contact you, and we can also know some advantages and disadvantages of your personality in the process of communication after getting to know you roughly.
In fact, sometimes it is good to know a little, which can help us get along with others better in life. But it's not absolute. You can't believe it completely. To know someone in life, or to get along with others. Only after a long period of contact, can we gradually understand what kind of person he is, and we can't judge his personality characteristics only by the constellation. So if a girl asks, just tell her directly and don't think too much.