# Answer 02

var width = window.innerWidth;
      var height = window.innerHeight;

      var stage = new Konva.Stage({
        container: 'container',
        width: width,
        height: height
      });

      var layer = new Konva.Layer();
      var mycircle = new Konva.Circle({
        x:300,
        y:175,
        radius:50,
        fill:'blue'
        
      });

var mytriangle = new Konva.RegularPolygon({
    x: 300,
    y: 175,
    sides: 3,
    radius: 30,
    fill: 'orange',
    shadowOffsetX : 20,
    shadowOffsetY : 25,
    shadowBlur : 40,
    opacity : 0.5,
    offset: {
        x: -100,
        y: -50
     }
});
   
      
      layer.add(mycircle);
      layer.add(mytriangle);
      stage.add(layer);

      // one revolution per 4 seconds
      var angularSpeed = 90;
      var anim = new Konva.Animation(function(frame) {
        var angleDiff = (frame.timeDiff * angularSpeed) / 1000;
        mytriangle.rotate(angleDiff);
     
      }, layer);

      anim.start();