JSFiddle - React, Tailwind, and code Playground

HTML

<div class="triangle"></div>

CSS

.triangle {
    width: 0;
    height: 0;
    border-top: 50px solid rgba(255%, 204%, 0%, 1);
    border-right: 0 solid transparent;
}

JavaScript

$(document).ready(function () {
    var windowWidth = $(window).width();
    $(".triangle").css({
        "border-top": windowWidth / 2 + 'px solid rgba(255%, 204%, 0%, 1)'
    });
    $(".triangle").css({
        "border-right": windowWidth / 1.5 + 'px solid transparent'
    });
});

$(window).resize(function () {
    var windowWidthR = $(window).width();
    $(".triangle").css({
        "border-top": windowWidthR / 2 + 'px solid rgba(255%, 204%, 0%, 1)'
    });
    $(".triangle").css({
        "border-right": windowWidthR / 1.5 + 'px solid transparent'
    });
});