JSFiddle - React, Tailwind, and code Playground

HTML

<a href='#'>
  <div class='tri-button'></div>
</a>

CSS

.tri-button {
  width: 0;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-bottom: 80px solid black;
}