var board = JXG.JSXGraph.initBoard('box1', {
boundingbox: [-10, 10, 10, -10],showNavigation:false, showcopyright: false, axis: false,
});
var p1 = board.create('point', [-1.0, 1.0],{face:'',label:{offset:[-5,10]}});
var p2 = board.create('point', [-5.0, -5],{face:'',label:{offset:[-10,-5]}});
var p3 = board.create('point', [5, -3.0],{face:'',label:{offset:[0,-5]}});
var arc1 = board.create('majorsector', [p1, p2, p3]);
var a1 = board.create('angle', [p3, p1, p2],{radius:2, name:"reflex angle", label:{offset:[-25,0]}});