JSFiddle - React, Tailwind, and code Playground

HTML

<canvas></canvas>

JavaScript

var r = 100;
var n = 10000;

var canvas = document.querySelector("canvas");
var context = canvas.getContext("2d");

canvas.width = 2 * r;
canvas.height = 2 * r;
context.transform(1, 0, 0, -1, r, r);

for (var i = 0; i < n; ++i) {
    var x = (Math.random() - .5) * 2 * r;
    var y = (Math.random() - .5) * 2 * Math.sqrt(r * r - x * x);
    
    context.fillRect(x, y, 1, 1);
}