Regular polygon
Polygons with more sides look more like circles. A polygon with an infinite number of sides is called an apeirogon. Polygons can be described in text by a special symbol called a Schläfli symbol. This symbol is written as curly brackets, with some numbers inside it, like {3}. {3} is a triangle. The number inside can also be a fraction. A Schläfli symbol of {5/2} is a five-pointed star.