This example renders a smiling face as a reusable React component, composed of separate SVG elements for the background circle, eyes, and mouth. The mouth uses d3’s `arc` generator to create a curved path based on configured radius and width values. All shapes are drawn in SVG within a single `<g>` container that translates the drawing to the center of a 960-by-500 viewport. The code explicitly defines constants for dimensions and positions, demonstrating a modular, parameter-driven approach to building simple visualizations with d3.v7 and React 17.