SO: Question

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r82/three.js"></script>
<script src="https://yume.human-interactive.org/examples/buffer-geometry/OrbitControls.js"></script>

JavaScript

const scene = new THREE.Scene();
  const camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000);
  camera.position.set(25, 25, 12);

  var material = new THREE.MeshBasicMaterial({color: 0x00fff0, side: THREE.DoubleSide});
  window.plane1 = new THREE.Mesh(new THREE.PlaneGeometry(10, 10), material);
  scene.add(plane1);

  plane1.position.set(0.3, 1, -2);
  plane1.rotation.set(Math.PI / 3, Math.PI / 2, 1);

  window.plane2 = new THREE.Mesh(new THREE.PlaneGeometry(10, 10), new THREE.MeshBasicMaterial({color: 0x0fff00, side: THREE.DoubleSide}));
  scene.add(plane2);


  // setup rest
  var pointLight = new THREE.PointLight(0xFFFFFF);
  pointLight.position.x = 10;
  pointLight.position.y = 50;
  pointLight.position.z = 130;
  scene.add(pointLight)

  const renderer = new THREE.WebGLRenderer({
    antialias: true
  });
  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.setClearColor(0x20252f);
  renderer.setPixelRatio(window.devicePixelRatio);
  document.body.appendChild(renderer.domElement);

  const controls = new THREE.OrbitControls(camera, renderer.domElement);

  animate();

  // TODO: What is the angle between plane1 and plane2?

  function animate() {
    requestAnimationFrame(animate);
    render();
  }

  function render() {
    renderer.render(scene, camera);
  }