createCanvas(400, 400);

  noLoop();

}

​

function circle_divide(m, e=1e-3, t=1e-10) {

  let u = -1, v = 3 / (m + 1);

  let points = [];

  while(u < -e) {

    u = 1e-10;

    for(let n = 0; n < m; n++) 

      u = (u + v) / (1 - u*v);

    v = v - u / (m + 1);

  }

  for(let n = 0; n < m; n++) {

    x = 2 / (1 + t*t) - 1;

    y = 2*t / (1 + t*t);

    t = (t + v) / (1 - t*v);

    points.push({x, y});

  } 

  return points;

}

​

function circle_divide2(n) {

  let v = createVector(1, 0);

  let points = [v.copy()];

  for(let p = 1; p < n; ++p) {

    points.push(v.rotate(2*PI/n).copy());

  }

  return points;

}

​

function draw() {

  background(220);

  noFill();

  stroke(100);

  let radius = 150;

  circle(width/2, width/2, 2*radius);

  let n = 5;

  strokeWeight(6);

  stroke("red");

  let points = circle_divide(n);

  for(let p of points) {

    point( width/2 + p.x * radius,

           width/2 - p.y * radius );

  }

  stroke("white");

  strokeWeight(3);

  points = circle_divide2(n);

  for(let p of points) {

    point( width/2 + p.x * radius,

           width/2 - p.y * radius );

  }

}