如何设置google图表图像大小

<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>

<div id="chart_div"></div>

google.charts.load('current', { 'packages': ['corechart'] });
google.charts.setOnLoadCallback(drawChart);

function drawChart() {
  var data = google.visualization.arrayToDataTable([
    ['Task', 'Hours per Day'],
    ['Work', 8],
    ['Sleep', 8],
    ['Eat', 2],
    ['Exercise', 2],
    ['Socialize', 4]
  ]);

  var options = {
    width: 400, // 设置图表宽度
    height: 300, // 设置图表高度
    chartArea: { width: '80%', height: '80%' } // 设置图表区域大小
  };

  var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
  chart.draw(data, options);
}