CodePen

HTML

            
              <html>
<body>
<div class="red"></div>
<div class="green"></div>
<div class="blue"></div>
<div class="yellow"></div>
</body>
</html>
            
          
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CSS

            
              .red{
  float:left;
  width:65%; 
  height:200px; 
  background:red;
  margin-bottom:10px;
}
.green{
  float:left;
  width:65%; 
  height:200px; 
  background:green;
}
.blue{
  width:34%; 
  height:500px; 
  background:blue; 
  margin-left:66%;
}
.yellow{
  clear:both; 
  width:100%; 
  height:50px; 
  background:yellow;
  margin:10px 0;
}
            
          
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JS

            
              
            
          
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