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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:

var b = JXG.JSXGraph.initBoard('jxgbox', {originX: 200, originY: 100, unitX: 50, unitY: 50});
var p1 = b.createElement('point',[0,0], {name:'X',style:6});
var p2 = b.createElement('point',[2,-1], {name:'B',style:6});
var p3 = b.createElement('point',[-2,-3], {name:'C',style:6});
var p4 = b.createElement('point',[-1,-1], {name:'D',style:6});
var p5 = b.createElement('point',[3,1], {name:'E',style:6});

Note that the "style" option is optional as is the parameter "name". Next we create a polygon through these five points "A" to "E".

var poly = b.createElement('polygon',["X","B","C","D","E"]);

Of course we can also use the JavaScript objects p1 to p5:

var poly = b.createElement('polygon',[p1,p2,p3,p4,p5]);

The result is the same: