Square (or any quadrilateral for that matter.) , triangle. -Daniel Hernandez
Yes
No, regular polygons are always convex and are shapes constructed using straight lines.concave polygons are irregular.
A closed, plain figure bounded by three or more line segments. These lines cannot be curved and they cannot intersect. A polygon must also fall on a single plane.
It must be a plane figure.It must be closed.It must be bounded by straight lines.These straight lines must not cross one another.