<div id="diagram"></div>
<script>
  $("#diagram").kendoDiagram({
    shapes: [{
      x: 10,
      y: 10,
      visual: function() {
        var group = new kendo.dataviz.diagram.Group();
        group.append(new kendo.dataviz.diagram.Polyline({
          points: [{x: 0, y: 0}, {x: 50, y: 0}, {x: 100, y: 100}],
          startCap: {
            type: "ArrowStart",
            fill: "red"
          }
        }));
        return group;
      }
    }]
  });
</script>