View source for Polygon

== Polygon defined by existing points ==
To construct a polygon an array of already constructed points is required. So we first have to construct at least three points:
<source lang="javascript">
var b1 = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-4, 2, 6, -4]});
var p1 = b1.create('point',[0,0], {name:'X',size:4});
var p2 = b1.create('point',[2,-1], {name:'B',size:4});
var p3 = b1.create('point',[-2,-3], {name:'C',size:4});
var p4 = b1.create('point',[-1,-1], {name:'D',size:4});
var p5 = b1.create('point',[3,1], {name:'E',size:4});
</source>
Note that the "style" option is optional as is the parameter "name".
Next we create a polygon through these five points "A" to "E".
<source lang="javascript">
var poly = b.create('polygon',["X","B","C","D","E"]);
</source>
Of course we can also use the JavaScript objects p1 to p5:
<source lang="javascript">
var poly = b.createElement('polygon',[p1,p2,p3,p4,p5]);
</source>
The result is the same:
<jsxgraph box="jxgbox" width="500" height="300">
var b1 = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-4, 2, 6, -4]});
var p1 = b1.create('point',[0,0], {name:'X',size:4});
var p2 = b1.create('point',[2,-1], {name:'B',size:4});
var p3 = b1.create('point',[-2,-3], {name:'C',size:4});
var p4 = b1.create('point',[-1,-1], {name:'D',size:4});
var p5 = b1.create('point',[3,1], {name:'E',size:4});

var poly = b1.create('polygon',[p1,p2,p3,p4,p5]);
var g = b1.create('glider',[0, 1, poly]);
</jsxgraph>


[[Category:Examples]]