JSFiddle - React, Tailwind, and code Playground

HTML

<canvas id="polygon" />

JavaScript

var polygon = document.getElementById('polygon').getContext('2d');
polygon.fillStyle = '#f00';
polygon.beginPath();
polygon.moveTo(0, 0);
polygon.lineTo(90,50);
polygon.lineTo(70, 70);
polygon.lineTo(0, 90);
polygon.closePath();
polygon.fill();