function setup() {
  let v1 = createVector(30, 50);
  print(v1.heading()); // 1.0303768265243125

  v1 = createVector(40, 50);
  print(v1.heading()); // 0.8960553845713439

  v1 = createVector(30, 70);
  print(v1.heading()); // 1.1659045405098132
}