This example shows a simple smiley face drawn with SVG primitives, consisting of a yellow circular head, two black eyes, and an arc-based mouth. The face is centered within a 960×500 viewport using a `<g>` transform. The code uses React for component rendering and D3 v7’s `arc` generator to compute the mouth path with specified inner and outer radii and angular extents. Circle elements define the head and eyes, with fixed offsets and radius values, while stroke styling creates the face’s outline.