JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block"></div>

CSS

.block {
  -webkit-clip-path: polygon(50% 100%, 100% 0, 100% 100%, 0 100%, 0 0);
  clip-path: polygon(50% 100%, 100% 0, 100% 100%, 0 100%, 0 0);
  width: 300px;
  height: 200px;
  background-color: black;
}