Chart.js v2.6：円グラフの出力値に矢印を追加

これで、 Chart.PieceLabel.jsを使用できます。 スライスの外側にラベルを付けます。

デモ

angular.module("app", ["chart.js"]).controller("ChartCtrl", function($scope) {

    $scope.labels = ["January", "February", "March", "April", "May", "June", "July"];

    $scope.data = [65, 59, 80, 81, 56, 55, 40];

    $scope.options = {
      pieceLabel: {
        render: 'label',
        fontColor: '#000',
        position: 'outside',
        segment: true
      }
    };

});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.2.1/Chart.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/angular.js"></script>
<script src="https://cdn.jsdelivr.net/angular.chartjs/latest/angular-chart.js"></script>
<script src="https://rawgit.com/beaver71/Chart.PieceLabel.js/master/build/Chart.PieceLabel.min.js"></script>
<div ng-app="app" ng-controller="ChartCtrl">
  <canvas id="pie" class="chart chart-pie"
         chart-data="data" chart-labels="labels" chart-options="options">
  </canvas> 
</div>