This example shows five distinct SVG shapes—a square, a rounded square, a line, a polyline, and a polygon—each rendered in its own small viewport using React components. The shapes are drawn with simple SVG elements like `rect`, `line`, and `polyline`, styled with fills and strokes. The code uses React 16 and D3 v6 for the overall structure, though no D3-specific visualization APIs are applied. All shapes are generated statically with fixed dimensions, displaying basic geometric forms without interaction or data binding.