A React component composes D3 arc shapes into a smiling face, drawn as SVG circles and a path. The face uses separate components for the yellow background circle, eyes, and mouth, with D3’s `arc()` generating the curved smile from specified radii and angles. React renders the SVG via `FaceContainer`, while the D3 arc API computes the mouth path. Built with d3.v5 and React 16.9, the example demonstrates declarative component reuse and geometry-based shape generation.