Untitled

<div id="container">

      <div id="header">lorem</div>

      <div class="table">

        <div id="content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Consequatur libero expedita commodi quas illo blanditiis dolores ab reprehenderit nostrum architecto unde pariatur numquam explicabo voluptate harum quae aspernatur officia temporibus!</div>

        <div id="sidebar">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Consequuntur earum fugit incidunt facere laborum neque molestiae sequi itaque! Labore sequi ut qui debitis nulla inventore consequatur ipsam reiciendis culpa cupiditate.</div>

      </div>

    </div>

#container {

  width: 800px;

  margin: 0 auto;

}

#header {

  width: 800px;

  background-color: red;

}

.table {

  display: table;

}

#content {

  width: 600px;

  background-color: blue;

  display: table-cell;

}

#sidebar {

  width: 200px;

  background-color: green;

  display: table-cell;

}