void setup() {
  size(400, 400);
  background(255);

  drawCircle(100, 100, 40);
  drawCircle(300, 100, 40);
  drawCircle(200, 300, 80);
}

void drawCircle(float x, float y, float r) {
  ellipse(x, y, r * 2, r * 2);
}