JSFiddle - React, Tailwind, and code Playground

HTML

<canvas id="canvas"></canvas>

JavaScript

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.moveTo(10,10);
ctx.lineTo(90,10);
ctx.lineTo(90,90);
ctx.lineTo(10,90);
ctx.save();
ctx.scale(0,0);
ctx.lineTo(45,45);
ctx.closePath();
ctx.restore();
ctx.strokeStyle= "black";
ctx.stroke();