createCanvas(400, 400);

  background(255);

  noFill();

  circle(width/2, height/2, 250);

  circle(width/2, height/2, 200);

  circle(width/2, height/2, 150);

  circle(width/2, height/2, 100);

  circle(width/2, height/2, 50);

}

​