​

function setup() {

  createCanvas(400, 400);

  noStroke();

  points = getShapePoints(3, 100, 90 * (PI / 180));

}

​

function draw() {

  background(220);

  push();

  translate(width / 2, height / 2);

  fill(255, 0, 255);

  beginShape();

  for(var i = 0; i < points.length; i++) {

    var pt = points[i];

    vertex(pt.x, pt.y);

  }

  endShape();

  pop();

}

​

function getShapePoints(sides, radius, rotation) {

  var angleStepSize = TWO_PI / sides;

  var points = [];

  for(var i = 0; i < sides; i++) {

    points.push({

      x: radius * cos(rotation + i * angleStepSize),

      y: radius * sin(rotation + i * angleStepSize)

    });

  }

  return points;

}