This example shows a modular, reusable smiley face built as a React component hierarchy, composed of separate circle and arc elements for the background, eyes, and mouth. It demonstrates how to combine React’s declarative component model with D3’s `arc` generator to produce SVG shapes. The `Face` component assembles the `FaceContainer`, `BackgroundCircle`, `Eyes`, and `Mouth` subcomponents, with all geometry controlled via props such as `eyeOffsetX`, `eyeRadius`, and `mouthRadius`. The resulting SVG is rendered to the DOM using `ReactDOM.render` with fixed pixel dimensions.