Two Equilateral Triangles with perpendicular

							var board = JXG.JSXGraph.initBoard('box1', {
        axis: true, boundingbox: [-10, 10, 10, -10], showcopyright: false,keepaspectratio: true, zoom: true, axis: false,showNavigation: false,
    });
var p1 = board.create('point', [-8, -5],{name:'A', size: 1,face:"", color:'blue', label: {offset:[-15,10], color:'blue'}} );	
var p2 = board.create('point', [2, -5],{name:'B', size: 1,face:"", color:'blue', label: {offset:[15,10], color:'blue'}} );	
var po1 =  board.create('regularpolygon',[p1,p2,3], {withLines: true, fillColor:'none',highlightFillColor:'#333',	vertices:{face:'',label: { color:'blue'}} });

var po2 =  board.create('regularpolygon',[ po1.vertices[2],p2, 3], {withLines: true, fillColor:'none',highlightFillColor:'#333',	vertices:{face:'',label: { color:'blue'}} });

var l1 = board.create('segment',[p1, po2.vertices[2]],{strokeWidth:1,dash:2})

var i1 =  board.create('intersection',[l1, po1.borders[1]],{face:'',label: {offset:[5,15]}})