A right trangle for definition of trigonometric functions

						JXG.Options.text.useKatex = true;
JXG.Options.axis.ticks.majorHeight = 10;
JXG.Options.axis.ticks.insertTicks = false;
JXG.Options.axis.ticks.ticksDistance = 100;
var board = JXG.JSXGraph.initBoard('box1', {
boundingbox:[-12, 18, 18, -12],showNavigation:false, showcopyright: false, axis: false,
});
var p1 = board.create('point', [-10, -8],{label:{offset:[5,25]}});
var p2 = board.create('point', [15, function(){return p1.Y()}],{size:''});
var p3 = board.create('point', [function(){return p2.X()},  8],{size:''});
var l1 = board.create('segment', [p1, p2],{strokeWidth:4});
var l2 = board.create('segment', [p2, p3],{strokeWidth:4});
var l3 = board.create('segment', [p3, p1],{strokeWidth:4});
var a1 = board.create('angle', [p2, p1, p3],{name:'α', radius:5,label:{offset:[-8,10]}});
 
txt1 = board.create('text',[function(){return p1.X()+(p2.X()-p1.X())/3},function(){return p1.Y()-2},function(){return 'Adjacent';}],{display:'internal',fontSize:16 });
txt2 = board.create('text',[function(){return p2.X()+2},function(){return p2.Y()+(p3.Y()-p2.Y())/5*4},function(){return 'Opposite';}],{display:'internal',rotate:270, fontSize:16 });
txt3 = board.create('text',[function(){return p1.X()+(p2.X()-p1.X())/3},function(){return p2.Y()+(p3.Y()-p2.Y())/5*2.3},function(){return 'Hypotenuse';}],{display:'internal',rotate:function(){
tan = (p3.Y()-p2.Y())/(p2.X()-p1.X());;ang = Math.atan(tan)*180/Math.PI; return ang;
}, fontSize:16 });