This example shows a smiling face built from SVG shapes, with a yellow circular background, two eyes, and an arc-based mouth. The rendering uses React components to structure the SVG elements, while D3’s `arc` generator computes the mouth path. The background circle’s radius and stroke width are defined by constants, and the eyes are positioned using fixed offsets from the center. The code relies on React 16.9 and D3 v7, with the SVG output rendered directly to the page.