JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myDiv">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco</div>

CSS

.myDiv {
    width: 300px;
    padding: 15px;
    text-align: right;
    background-color: lightblue;
    position: relative;
    border: 1px solid black;
}

.myDiv::before {
    content: "";
    position: absolute;
    bottom: -20px;
    right: 20px;
    border-right: 20px solid lightblue;
    border-bottom: 20px solid transparent;
}