This example renders a basic smiley face using React and D3 v7, drawing SVG shapes on a 960×500 canvas. It shows a yellow circle with a black stroke for the head, two black eye circles positioned symmetrically, and a smile created with the `arc` generator from D3. The arc uses inner and outer radii with start and end angles to form a mouth shape. All geometry is computed from center coordinates, radius, and offset variables, then transformed into place using an SVG group element.