JSFiddle - React, Tailwind, and code Playground

HTML

<div id="output"></div>

JavaScript

var shape = {
  name: 'shape',
  toString: function () {
    return this.name;
  }
};
var twoDee = {
  name: '2D shape',
  dimensions: 2
};
var triangle = multi(shape, twoDee, {
  name: 'Triangle',
  getArea: function () {
    return this.side * this.height / 2;
  },
  side: 5,
  height: 10
});


function multi() {
  var n = {},
    stuff, j = 0,
    len = arguments.length;
  for (j = 0; j < len; j++) {
    stuff = arguments[j];
    for (var i in stuff) {
      n[i] = stuff[i];
    }
  }
  return n;
}

function print(info) {
  var output = document.getElementById("output");
  output.innerHTML = output.innerHTML + info + "<br>";
}