title: Find out what height would have my image if i will resize the width to another value
body: <p>I have a twitter bootstrap carousel in which I have images and iframes. Images work perfectly because they have img-responsive class and they resize. The iframes don't work like that. I have to give them a width and a height and change their width and height whenever the user resizes the browser. </p>
  
  <p>The carousel can contains only images, only iframes, or images and iframes in the same time.</p>
  
  <p><strong>How can I make the iframes work like the images? Have the same dimensions, resizes in the same way?</strong> </p>
  
  <p>My images are <code>750 x 427px</code>. The thing that passes my mind is to give the iframes width 100% of the container because this work and after this I have to find the height considering that if the width is for example 300px the height should direct proportional with the image dimensions which are <code>750 x 427px</code>.</p>
  
  <p><strong>We can simply use the rule of three ? Or there is somehthing more complex using image ratio?</strong></p>