Are cursives and circle polygons, or two other different things?

Question

I understand that any polygon always contain three or more points (translated in Hebrew "dots", hence my previous confusion and deleted question), but never two points, because a geometric set (translated in Hebrew as "shape", hence my previous confusion and deleted question) with only two dots, is only a line segment.

My problem

With this understanding, I am in problem about how to define cursive shapes (such as the letters C or O that I used here to represent a perfect half circle and a perfect circle although they aren't), let alone a real perfect circle (which I understand to have a "world of its own" in mathematics).

My question

Are cursives and circle polygons, or two other different things (and possibly different from one another)?
_{(In first glimpse I thought "maybe a cursive is a line segment?")}

Answer 1

Polygons are made of straight line segments.

You may generalize the concept by admitting curved edges; that might be called curvilinear polygons.

A circle is a circle. A closed, convex curve without angular points may be called an oval.

The portion of a straight line between two points is a segment. The portion of a curve between two points is an arc.

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Circles are the only curves with a constant curvature, i.e. that can "slide on themselves". There are millions other types of curves obtained from analytical equations.

In the computerized typesetting systems, the curves are usually built from conics and parametric cubics (such as the well-known Bezier curves).

Answer 2

Polygons are vertices joined by (straight) line segments.

Circles are, well, circular. They are the set of points equidistant from the circle's center.

Of course, these are different shapes. And there are other shapes as well. If you take a pencil and draw some curve-y (closed?) line on a sheet of paper, chances are it won't be a circle. You might draw, say, an ellipse, a lemniscate or something else entirely. Most things don't even have names!