var x0 = 0.4;
var y0 = 0.3;

var x1 = 0.7;
var y1 = 0.5;

var x2 = 0.2;
var y2 = 0.9;

var x3 = x0 + ((y1 - y0) / (y2 - y0)) * (x2 - x0);
var y3 = y1;

var x4 = x2 + ((x1 - x2) / (y1 - y2)) * (y0 - y2);
var y4 = y0;

var x5 = x0;
var y5 = y1 + ((x1 - x0) / (x2 - x1)) * (y1 - y2);