Smiley Face Part 4
A smiley face rendered as an SVG using React components and D3’s arc generator for the mouth. The face is built from a yellow background circle, two dark eyes, and a thick black mouth arc, all centered via a translate transform. React 16 manages the SVG elements, while D3 v5 calculates the mouth’s path from angular start and end points. The code defines reusable components like BackgroundCircle and imports only the arc function from D3, demonstrating a minimal integration of both libraries.