Let's make a face with d3
This example draws a single circle in an SVG, using D3 v5 to select the root `<svg>` element and append a `<circle>` shape. The circle’s radius is set to half the viewport height (250) and its center is placed at the middle of a 960×500 canvas. The code uses `d3.select`, `append`, and `attr` methods to position the shape, with a fixed `height` and `width` defined in JavaScript. No data source is used; the visualization is purely geometric and static.