var x2;

var x3;

var y1;

var y2;

var y3;

​

function setup() {

  createCanvas(600, 600);

  initPoints();

}

​

//taken from professor Golan Levin

function draw() {

  background(50);

  fill(255, 200, 100);

  noStroke();

  triangle(x1, y1, x2, y2, x3, y3);

​

  noStroke();

  fill(255);

  ellipse(x1, y1, 15, 15);

  ellipse(x2, y2, 15, 15);

  ellipse(x3, y3, 15, 15);

​

  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);

​

  push();

  noFill();

  strokeWeight(2);

  stroke(255);

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

  pop();

​

  ellipse(cx, cy, 10);

​

}

​

function mousePressed() {

  initPoints();

}

​

function initPoints() {

  x1 = width * random(0.2, 0.8);

  x2 = width * random(0.2, 0.8);

  x3 = width * random(0.2, 0.8);

  y1 = height * random(0.2, 0.8);

  y2 = height * random(0.2, 0.8);

  y3 = height * random(0.2, 0.8);

​

}