​

let r = 90;  //radius

let ang; //central angle

let n = 3;  //number of sides

let v = 0; //v controls rotating

let area;

​

function setup() {

  createCanvas(400, 400);

  angleMode(RADIANS);

  ang = (2 * PI) / n; 

  //v = ang;

}

​

function draw() {

  background(0);

  stroke(255);

  strokeWeight(3);

  noFill();

​

  //creating the shape

  beginShape();

  for (var i = 0; i < n; i++) {

    vertex(

      width / 2 + r * cos(ang * i + v),

      height / 2 + r * sin(ang * i+v)

    );

  }

​

  endShape(CLOSE);

  //creating the spokes

  strokeWeight(1)

  for (var i = 0; i < n; i++) {

    line(width/2,height/2,width / 2 + r * cos(ang * i + v),

      height / 2 + r * sin(ang * i +v))

  }

  v += .002; //rate of rotation

  area = n*1/2*r*r*sin(ang);

  text('Area = ' + area,10,40)

  //console.log(area);

}

​