A "half" pie

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.24/browser.js"></script>
<script src="https://npmcdn.com/[email protected]/dist/react-with-addons.min.js"></script>
<script src="https://npmcdn.com/[email protected]/dist/react-dom.min.js"></script>
<script src="https://npmcdn.com/prop-types/prop-types.min.js"></script>
<script src="https://npmcdn.com/recharts/umd/Recharts.min.js"></script>
<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

CSS

body {
  margin: 0;
}
#container {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  padding: 10px;
  width: 800px;
  height: 800px;
  background-color: #fff;
}

Babel + JSX

const {PieChart, Pie, Legend} = Recharts;

const data = [{name: 'Group A', value: 400}, {name: 'Group B', value: 300}]

const COLORS = ['#0088FE', '#00C49F'];

const StraightAnglePieChart = React.createClass({
	render () {
  	return (
    	<PieChart width={800} height={400}>
        <Pie startAngle={-60} endAngle={240} data={data} cx={200} cy={200} outerRadius={80} innerRadius={40} fill="#8884d8">
                  	{
          	data.map((entry, index) => <Cell fill={COLORS[index % COLORS.length]}/>)
          }
        </Pie>
       </PieChart>
    );
  }
})

ReactDOM.render(
  <StraightAnglePieChart />,
  document.getElementById('container')
);