Hi!
Here are several ways to look at this, One is to say that the number of sides it has is zero. The circle is a continuous curve. It has no "flat spot" and might be said to have no sides.?
On the other hand, it could be argued that it has infinitely many sides. A circle might be viewed as a polygon with an infinite number of sides.?
The class clown has offered that the circle has two sides - an inside and an outside. Also, if one considers that the circle delineates a disk, it has a top and bottom.?
Lastly, and perhaps "bestly" in regards to circles, the term "side" has no meaning when applied to a circle. The side of a circle is undefined. Some mathematicians lean that way. A special note here. The term "undefined" is not zero nor is it infinity. It's undefined. Like division by zero. That's undefined, too. Dividing a number by zero is not something we can't calculate, it's something we can't define. The side or sides of a circle is or are undefined.
Regards.