Lets make a face
This example assembles a smiling cartoon face from basic D3 shapes, including a bright yellow circular head, black eyes, and a curved arc mouth. It showcases manual SVG construction through D3 selections and the `d3.arc` generator for the mouth’s path. The face is centered by translating a group element, while eyes are positioned with explicit `cx` and `cy` offsets. The code relies on D3 v5’s `select`, `arc`, and attribute methods, rendering entirely in SVG with no external data source, demonstrating coordinate math and layout composition.