JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

div {
    width: 0; 
	height: 0; 
	border-left: 20px solid transparent;
	border-right: 20px solid transparent;
	border-top: 20px solid #f00;
    -webkit-filter: drop-shadow(0 1px 2px #000);
    filter: drop-shadow(0 1px 2px #000);
}