JSFiddle - React, Tailwind, and code Playground

by Gaurav Singh

HTML

<div id="container">
    <div id="triangle-topleft"></div>
  </div>

CSS

#container {
  height: 100px;
  width: 100px;
  overflow: hidden;
  background-image: url(http://www.webdesign.org/img_articles/14881/site-background-pattern-07.jpg);
}

#triangle-topleft { 
  width: 0; 
  height: 0; 
  border-top: 100px solid gray; 
  border-right: 100px solid transparent;
}