This example shows a smiling face built from a yellow circle, two eyes, and a curved mouth, all rendered as SVG shapes. The face is centered in a 960 by 500 viewport using React components and D3’s `arc()` generator to create the mouth path. The code uses `d3.arc` with inner and outer radii and start/end angles to form the smile, while React handles the circle elements and DOM rendering. The face is drawn with a fixed stroke width and offset eye positions.