JSFiddle - React, Tailwind, and code Playground

HTML

<div id="shape"><div>

CSS

#shape{
    width: 100px;
    height: 100px;
    background-color: lightblue;
    -webkit-clip-path: polygon(100% 100%, 0 100%, 0 0, 52% 16%, 100% 0);
    clip-path: polygon(100% 100%, 0 100%, 0 0, 52% 16%, 100% 0);
}