The length of AC is 3 times the length of CD

						var board = JXG.JSXGraph.initBoard('box1', {
boundingbox: [-10, 10, 10, -10],showNavigation:false, showcopyright: false, axis: false,
});
var p1 = board.create('point', [-9, 2.0],{size:1});
var p2 = board.create('point', [-3, 2.0],{size:1});
var p3 = board.create('point', [3, 2.0],{size:1});
var p4 = board.create('point', [7, 2.0],{size:1});
var l1 = board.create('segment', [p1,p4]);