JSFiddle - React, Tailwind, and code Playground
HTML
<div class="bubble">
nice
</div>
CSS
.bubble {
margin-top: 100px;
position: relative;
width: 200px;
height: 100px;
text-align: center;
line-height: 100px;
background-color: orange;
-webkit-border-radius: 30px;
-moz-border-radius: 30px;
border-radius: 30px;
}
.bubble:after {
content:"";
position:absolute;
bottom:-20px; /* value = - border-top-width - border-bottom-width */
left:50px; /* controls horizontal position */
border-width:20px 0 0 20px; /* vary these values to change the angle of the vertex */
border-style:solid;
border-color: orange transparent;
/* reduce the damage in FF3.0 */
display:block;
width:0;
}