     Holds a 2D floating-point size. <a href="dart-ui/Size-class.html">[...]</a>
        </dd>
        <dt id="StrutStyle">
          <span class="name "><a href="dart-ui/StrutStyle-class.html">StrutStyle</a></span>         
        </dt>
        <dd>
          See also: <a href="dart-ui/StrutStyle-class.html">[...]</a>
        </dd>
        <dt id="Tangent">
          <span class="name "><a href="dart-ui/Tangent-class.html">Tangent</a></span>         
        </dt>
        <dd>
          The geometric desc