a circle is a circle - no sides at all
Archimedes created the formula for measuring the circumference of a circle he used many-sided polygons, both inside and out to approximate it.
a semi-circle
Zero in the normal course of events. You could say you can approximate a circle by an infinite-sided polygon, and then you would have infinite sides and corners. Or you could say a circle has an inside and an outside.
Pentagram
it has so many sides it looks like a circle.
a circle is a circle - no sides at all
a circle
Circle
There is no such thing as a 1 sided shape nor a two sided shape.
A 9-sided "circle" is an nonagon or enneagon.
Archimedes created the formula for measuring the circumference of a circle he used many-sided polygons, both inside and out to approximate it.
a circle
A circle!
Circle.
a circle
a circle