A trangle geometric shape

						var board = JXG.JSXGraph.initBoard('box1', {
boundingbox: [-15, 15, 15, -15], showcopyright: false,keepaspectratio: true,zoom: true,axis: false, showNavigation: false
});

var p1 = board.create('point', [-8, -8],{name:'A', size: 1, color:'blue',face:'',fixed:true, label: {offset:[-25,10], color:'blue'}} );

var p2 = board.create('point', [3, -8],{name:'D', size: 1, color:'blue',face:'', fixed:true,label: {offset:[-25,10], color:'blue'}} );

var p3 = board.create('point', [-6, 8],{name:'B', size: 1, color:'blue', face:'', fixed:true,label: {offset:[-25,10], color:'blue'}} );
var l1 = board.create('segment', [p1, p2],{strokeWidth:2});



var l2 = board.create('parallel', [p3,l1],{visible:false});

var l3 = board.create('segment', [p1, p3])

var p4 = board.create('point', [-2, 8],{visible:false} );

var l4 = board.create('segment', [p3, p4],{visible: false});

var Inpt = [[p3,p4,l4],["C"],{d:function(){return l3.L()-l1.L();}}];
  
var pl =  board.create('pointofline',Inpt,{line:{}, point:{face:'', color:'blue', }});

var l5 = board.create('segment', [p3, pl.C],{strokeWidth:2});
var l6 = board.create('segment', [p2, pl.C],{strokeWidth:2});

var mp1 =  board.create('midpoint', [l6],{name:'E', size: 1,face:"", color:'blue', label: {offset:[10,0], color:'blue'}} );
var l7 = board.create('segment', [p1, mp1],{strokeWidth:2});
var l8 = board.create('segment', [p3, mp1],{strokeWidth:2});