Line segments are actually graphs, and so are lines, circles, rectangles, curves, charts and so on.

Graphics is a form of expression that takes geometric lines and symbols as carriers and reflects various characteristics and changing laws of things.

A figure is a closed pattern formed by connecting three or more line segments in turn, which is called a figure.

I don't know where you read the definition of your figure, but I've never seen a figure with such a definition.

If your definition holds, is a circle a figure?