Polygon- a closed plane figure with straight sides.
A polygon is a figure or shape that has straight sides and the sides have to be in the same plane. So a polygon does not have to be a pentagon,hexagon, triangle or any shape you know of. It can have 1,468 and as long as the sides are straight and they are in the same plane it is a polygon. But a circle for instance does not have straight sides actually it has no sides at all. But a shape like this is a polygon straight lines and all.