var x2;

var x3;

var y1;

var y2;

var y3;

​

function setup() {

  createCanvas(600, 600);

  initPoints();

}

​

function draw() {

  background('lightgray');

​

  //strokeWeight(1);

  ellipse(x1, y1, 10, 10);

  ellipse(x2, y2, 10, 10);

  ellipse(x3, y3, 10, 10);

  line(x1, y1, x2, y2);

  line(x2,y2, x3, y3);

  line(x3,y3, x1, y1);

  var ma = (y2 - y1) / (x2 - x1);

  var mb = (y3 - y2) / (x3 - x2);

  var cx = (ma * mb * (y1 - y3) + mb * (x1 + x2) - ma * (x2 + x3)) / (2 * (mb - ma));

  var cy = -1 * (cx - (x1 + x2) / 2) / ma + (y1 + y2) / 2;

​

  var dx = x1 - cx;

  var dy = y1 - cy;

  var radius = sqrt(dx * dx + dy * dy);

​

  noFill();

  ellipse(cx, cy, 10, 10);

  ellipse(cx, cy, radius * 2, radius * 2);

}

​

function mousePressed(){

  initPoints();

}

​

function initPoints() {

  x1 = width * random(0.1, 0.8);

  x2 = width * random(0.1, 0.8)

  x3 = width * random(0.1, 0.8);

  y1 = height * random(0.1, 0.8);

  y2 = height * random(0.1, 0.8);

  y3 = height * random(0.1, 0.8);

}