<p> Donner la mesure en radians des angles mesurés par le rapporteur ci-contre.</p>
<p> </p>
<p> </p>
<!--
    
    var p0 = brd.create('point',[0,0],{name:'0',fixed:true});
    var px = brd.create('point',[{R},0],{name:'X',fixed:true});
    var p1 = brd.create('point',[{xa},{ya}],{name:'A',fixed:true});
    var p2 = brd.create('point',[{xb},{yb}],{name:'B',fixed:true});
    var p3 = brd.create('point',[{xc},{yc}],{name:'C',fixed:true});
    var p4 = brd.create('point',[{xd},{yd}],{name:'D',fixed:true});
    var L0 = brd.create('segment', [p0, px],  {strokeColor:'red',strokeWidth:2,fixed:true});
    var L1 = brd.create('segment', [p0, p1],  {strokeColor:'blue',strokeWidth:2,fixed:true});
    var L2 = brd.create('segment', [p0, p2],  {strokeColor:'blue',strokeWidth:2,fixed:true});
    var L3 = brd.create('segment', [p0, p3],  {strokeColor:'blue',strokeWidth:2,fixed:true});
    var L4 = brd.create('segment', [p0, p4],  {strokeColor:'blue',strokeWidth:2,fixed:true});

    var AL = brd.create('slider', [[-3,-3],[3,-3],[1,2,6]], {name:'&alpha;'});
     
    var im = brd.create('image', [urlImg, [-{R},0],[2*{R},{R}]],{fixed:true});
-->
<p>
<script type="text/javascript" src="http://jsxgraph.org/distrib/jsxgraphcore.js"></script>
<script type="text/javascript" src="http://jsxgraph.org/distrib/geonext.min.js"></script>
</p>
<div id="jxgbox" class="jxgbox" style="width: 500px; height: 500px;"> </div>
<p>
<script type="text/javascript">// <![CDATA[
(function() {  // définir comme fonction
var brd = JXG.JSXGraph.initBoard('jxgbox', {
        boundingbox: [-5, 5, 5, -5],
        axis: true,
        grid: true,
        showFullscreen: true,
        showNavigation:false,
        showCopyright:false
    });
   var p0, px, pv, c, a, s;
/*
var a = board.create('angle', [p1, p2, p3], {
	 radius: 1,
  name: function() {
  	return JXG.Math.Geometry.trueAngle(p1, p2, p3).toFixed(1) + '°';
  }});
*/
  
    var p0 = brd.create('point',[0,0],{name:'0',fixed:true});
    var px = brd.create('point',[{R},0],{name:'X',fixed:true});
    var pv = brd.create('point',[{xa},{ya}],{name:'A'});//point variable qui sera liée au curseur

    var L0 = brd.create('segment', [p0, px],  {strokeColor:'red',strokeWidth:2,fixed:true});
    var L1 = brd.create('segment', [p0, pv],  {strokeColor:'blue',strokeWidth:2,fixed:true});

    c1 = brd.create('circle',[p0, px]); // définir le cercle de centre p0 et rayon R
    
    a = brd.create('angle',[px, p0, pv], {radius: {R},name: function() {
  	return JXG.Math.Geometry.trueAngle(px, p0, pv).toFixed(1) + '°';}
  });
  //  s = brd.create('slider', [[-3,-3],[3,-3],[0, Math.PI*0.5, 2*Math.PI]], {name:'&alpha;', snapWidth: Math.PI*0.1});
    s = brd.create('slider', [[-3,-3],[3,-3],[0, {a}, 2*Math.PI]], {name:'&alpha;', snapWidth: Math.PI*0.1});

    a.setAngle(function() {
        return s.Value();
    });

    
    })();
// ]]></script>
</p>