JSFiddle - React, Tailwind, and code Playground

HTML

<div class="triangle-haut">
                                
    </div>
        <div class="triangle-bas">
                                
    </div>

CSS

.triangle-haut{position:absolute;
 width: 0px;
 height: 0px;
 border-top: 451px solid #414141;
 border-left: 751px solid transparent ;


}

.triangle-bas{position:relative;
 width:0px;
 height:0px;
 border-color:transparent transparent #414141;
 border-style: solid;
 border-width:0px 751px 451px 0px;

}