JSFiddle - React, Tailwind, and code Playground

HTML

<div class="speech-bubble"></div>

CSS

.speech-bubble {
   margin-left: 20px;
   width: 120px; 
   height: 80px; 
   background: purple;
   position: absolute;
   border-radius: 10px;
}
.speech-bubble:before {
   content:"";
   position: absolute;
   width: 0;
   height: 0;
   border-top: 13px solid transparent;
   border-right: 26px solid purple;
   border-bottom: 13px solid transparent;
   margin: 13px 0 0 -25px;
}