This example renders a smiley face as an SVG graphic using React for component structure and D3’s `arc` generator to create the mouth. The face consists of a yellow circle with a black stroke, two eye circles, and a mouth path drawn via an arc with specified inner and outer radii and angular spans. D3 v5 and React 16.9 are loaded from CDNs, with the SVG output centered and scaled to a 960×500 viewport. The code defines all geometric parameters as constants, making the layout explicit and easily adjustable.