HTML Starter
This example uses React and D3 v5 to render a smiling face emoji as an SVG graphic. The code defines the face using SVG circles for the head and eyes, while D3’s `arc` generator constructs the mouth path with specified inner and outer radii and angles. The React component returns an SVG tree with a yellow circle, white eye highlights, and black pupils, all positioned via transformation variables. The HTML page loads React, ReactDOM, and D3 from CDNs, then mounts the component into a root div.