A trangle geometric shape

						var board = JXG.JSXGraph.initBoard('box1', {
boundingbox: [-10, 10, 10, -10], showcopyright: false,keepaspectratio: true,zoom: true,axis: false, showNavigation: false
});

var Inpt = [60,60 ,10,["B","C","A"],'AAS'];
var tri = board.create('triangle',Inpt,{D:"LT",'line':{withLabel:false,strokeColor:'blue',strokeWidth:2},'angle':{visible:false,strokeColor:'red',strokeWidth:1},});

var a = board.create('slider',[[-4,-8],[4,-8],[0,4,10]], {name:'a'});

var Inpt = [[tri.B, tri.A],["E"],{d:function(){return a.Value();}}];
var pl1 =  board.create('pointofline',Inpt,{line:{strokeColor:'blue'},point:{size:1}});

var Inpt = [[tri.A, tri.C],["F"],{d:function(){return 10+a.Value();}}];
var pl2 =  board.create('pointofline',Inpt,{line:{strokeColor:'blue'},point:{size:1}});

var l4 = board.create('segment', [pl1.E, pl2.F]);

var i1 =  board.create('intersection', [tri.BC, l4],{size:1});
var l5 = board.create('segment', [tri.C, pl2.F],{dash:2});

var par1 =  board.create('parallel', [ pl2.F,tri.BC],{visible:false});

var i2 =  board.create('intersection', [tri.AB, par1],{size:1});

var l6 = board.create('segment', [i2, pl2.F],{dash:2});


var l7 = board.create('segment', [i2, tri.B],{dash:2});