Hello HTML
This example renders a smiley face using React and D3’s `arc` function. The SVG contains a yellow circle for the face, two black eyes positioned via offset constants, and a mouth drawn as an arc path with `d3.arc()`. The code defines a React component that returns SVG elements, with sizes and coordinates computed from fixed width and height values. It demonstrates combining React’s declarative JSX with D3’s geometry utilities inside an SVG rendering, using d3.v6 and React 17.