title: Proportional layout for iPhones (from 5 to 6 Plus) with Size Classes
body: <p>I have passed through a number of tutorials about Size Classes but still I cannot figure out one thing.</p>
  
  <p>iPhone 5, iPhone 6 and iPhone 6 Plus have absolutely the same screen aspect ratios, so I want them to use the same content layout. By saying the same I mean proportional to width and height of the screen.</p>
  
  <p>But! I cannot find a way to make it proportional for all iPhones!</p>
  
  <p>There are just a few constraints that truly support proportions: "Aspect Ratio", "Same Width" + "Multiplier", "Same Height" + "Multiplier"</p>
  
  <p>Constrains, such as Leading Edges, Horizontal Center In Container, all Pin constraints operate with absolute values in logical points, and all iPhones' screens have different sizes in logical points; thereby I cannot achieve the same picture on all iPhones.</p>
  
  <h2>Update</h2>
  
  <p>I'm adding an image to explain what I want to achieve:</p>
  
  <p><img src="https://i.stack.imgur.com/AC05B.jpg" alt="enter image description here"></p>