JSFiddle - React, Tailwind, and code Playground

HTML

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

JavaScript

var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');

canvas.width = 100;
canvas.height = 100;

var cx = canvas.width/2;
var cy = canvas.height/2;

var x = -10;
var y = -10;
var w = 20;
var h = 20;
var deg = Math.PI/180;

ctx.save();

ctx.translate(cx, cy);
ctx.rotate(45 * deg);

ctx.fillRect(x, y, w, h);

ctx.restore();