title: how can i rotate a shape in canvas,html5?
body: <p>im tried to rotate a line with this</p>
  
  <pre><code>window.onload= function(){
          var canvas=document.getElementById("foo");
          var context=canvas.getContext("2d");
  
          context.moveTo(250, 50);
          context.lineTo(250, 250);
          context.stroke();
          context.rotate(0.30);
  
      };
  </code></pre>
  
  <p>what am i doing wrong? i think im missing some steps. can anyone explain?</p>