Fork of Smiley Face Part III
This example shows a classic smiley face rendered as an SVG graphic, composed of a yellow circle, two black eyes, and an arc-shaped mouth. The face is drawn using React components that compute SVG circle and path elements, with the mouth generated through D3’s `arc` function. The code imports React and ReactDOM for rendering, and uses `d3.arc` to define the mouth’s inner and outer radii and angular range. All shapes are positioned relative to a central transform, demonstrating a simple integration of React’s declarative UI with D3’s geometry utilities.