JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

div {
    width: 118px; /* 118 = rectangle width - 2 */
    height: 33px; /* 33 = shape height - 2 */
    border: 1px solid #007bff;
    background-color: white;
}

div:before {
    content: '';
    border-right: 30px solid transparent; /* 30 = triangle width */
    border-bottom: 35px solid #007bff; /* 35 = shape height */
    float: left;
    margin-left: 119px; /* 121 = rectangle width - 1 */
    margin-top: -1px; /* always 1*/
}

div:after {
    content: '';
    border-right: 29px solid transparent; /* 29 = triangle width - 1 */
    border-bottom: 33px solid white; /* 33 = shape height - 2 */
    float: left;
    margin-left: 118px; /* 120 = rectangle width - 2 */
    margin-top: -34px; /* 34 = shape height - 1 */
}