title: bootstrap 3 make div height 50% of the parent div
body: <p>I'm using Bootstrap 3 and I need to set two <strong>div</strong> elements disposed vertically within a <strong>div</strong> parent, and inside each div there should be an image. All image should be responsive and fit the div height, so the image of <strong>div1</strong> should be larger</p>
  
  <pre><code> _____________
  |div1 | div2  |
  |     |-------
  |_____|_div3__|
  </code></pre>
  
  <p>I put a code example here, but it doesn't work.
  How can I fix this?</p>
  
  <p><a href="http://jsfiddle.net/fstarred/tonq8wdq/" rel="nofollow">http://jsfiddle.net/fstarred/tonq8wdq/</a></p>