What has 3 rings and a big top can be stretched out?

This sounds like a riddle! The answer is a circus tent.

Here's why:

* 3 rings: Circuses traditionally have three rings for different acts.

* Big top: This is the common name for the large tent used in circuses.

* Can be stretched out: The tent fabric is stretched out over a frame to create the large space.

Let me know if you'd like to try another riddle! 😊