This example builds a smiley face using React components and D3’s `arc` generator to draw the mouth. The face consists of a yellow circle with a black stroke, two eye circles positioned via offsets, and a mouth path created from an arc with specified outer radius and angles. The SVG is centered through a group transformation, with dimensions fixed at 960 by 500 pixels. React handles the DOM rendering, while D3 v5 provides the geometric arc computation for the mouth shape.