JSFiddle - React, Tailwind, and code Playground

HTML

<div class="item">
</div>

CSS

.item {
  width: 100%;
  height: 100px;
  background-color: red;
  -webkit-clip-path: polygon(100% 0, 0 0, 0 100%);
  clip-path: polygon(100% 0, 0 0, 0 100%);
}