This example demonstrates a radial area chart generated with D3.js, where a circular path alternates between outer radii of 80 and 40 pixels while maintaining an inner radius of 20. The visualization encodes nine angular data points from 0 to 2π, filling the resulting petal-like shape with a light gray color. The code uses `d3.radialArea()` with `.angle()`, `.innerRadius()`, and `.outerRadius()` accessors to compute the SVG path data, which is then appended to a `<g>` element. The chart renders in an SVG container sized 700 by 200 pixels, with data provided as an array of angle-radius pairs.