your [login to view URL] class should be separate from the GUI class. you are to pass the points generated in PiMonteCarle to Animator of GUI class to be drawn on canvas.
PiMonteCarle runs on different thread. bonus mark if you use ExecutorService instead of Thread class.
in your canvas draw a circle first then the points. points in circle should be green and rest red. use [login to view URL]() to set the color before drawing a dot using [login to view URL]();