JSFiddle - React, Tailwind, and code Playground
HTML
<div class='trapezoid'></div>
CSS
.trapezoid {
display: inline-block;
overflow: hidden;
margin: 0 3em;
/**outline: solid 1px;/**/
width: 10em;
height: 10em;
transform: rotate(45deg);
-webkit-transform: rotate(45deg);
}
.trapezoid:before {
display: block;
background: red;
content: '';
}
.trapezoid:before {
width: 20em; height: 3em;
transform: rotate(-45deg) translate(-4.142em, -2.6em);
-webkit-transform: rotate(-45deg) translate(-4.142em, -2.6em);
}