clip path alternative for Firefox and IE9+
<p>I'm trying to build something like a rooftop using CSS clip paths.
Unfortunately I noticed IE and Firefox do not support clip path.
My question: What is a good alternative to build polygons which are compatible with IE and Firefox. Also these polygons need to have shadows and some text-content.</p>

<p>Here is my clip path example:    </p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-css lang-css prettyprint-override"><code>.roof-left {
 width: 280px;
 height: 280px;
 background: #1e90ff;
 -webkit-clip-path: polygon(0 54%, 100% 21%, 100% 100%, 0% 100%);
    clip-path: polygon(0 64%, 100% 21%, 100% 100%, 0% 100%);
    -webkit-box-shadow: 2px 2px 5px 0px rgba(0,0,0,0.75);
    -moz-box-shadow: 2px 2px 5px 0px rgba(0,0,0,0.75);
    box-shadow: 2px 2px 5px 0px rgba(0,0,0,0.75);

}
.roof-content-left {
    padding-top: 60%;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="roof-left"&gt;
  &lt;div class="roof-content-left"&gt;
   Whatever
  &lt;/div&gt;
&lt;/div&gt;</code></pre>
</div>
</div>
</p>