JSFiddle - React, Tailwind, and code Playground

HTML

<div class="left"> </div>
<div class="right"> </div>

CSS

.left, .right {
    position: relative;
    height: 100px;
    width: 200px;
    background: #000;
    float: left;
}

.left:after {
    content: '';
    line-height: 0;
    font-size: 0;
    width: 0;
    height: 0;
    border-top: 100px solid #000;
    border-bottom: 50px solid transparent;
    border-left: 0px solid transparent;
    border-right: 50px solid transparent;
    position: absolute;
    top: 0;
    right: -50px;
}

.right {
    margin-left: 60px;
    width: 100px;
}

.right:before {
    content: '';
    line-height: 0;
    font-size: 0;
    width: 0;
    height: 0;
    border-top: 50px solid transparent;
    border-bottom: 100px solid #000;
    border-left: 50px solid transparent;
    border-right: 0px solid #000;
    position: absolute;
    top: -50px;
    left: -50px;
}