Smiling Face Part 1
This example builds a smiling face in SVG using React components. The face is composed of a yellow circle, two eyes, and a mouth rendered as an arc. The mouth’s shape is created with D3’s `arc()` generator, specifying inner and outer radii and angle parameters. The code uses React’s component model to structure the face, with separate components for the face, eyes, mouth, and SVG container. The final rendering is a static SVG with no interaction.