Make the pie chart to take the whole space of the container

In order for the pie to take the whole width/height of the container you will need to:

1. Disable callouts / labels;
   
2. Set all margins to zero;
   
3. Disable slice pullout functionality.

Like this:

chart.labelsEnabled = false;
chart.autoMargins = false;
chart.marginTop = 0;
chart.marginBottom = 0;
chart.marginLeft = 0;
chart.marginRight = 0;
chart.pullOutRadius = 0;

Or if you are using JSON config:

AmCharts.makeChart("chartdiv", {
...
  labelsEnabled: false,
  autoMargins: false,
  marginTop: 0,
  marginBottom: 0,
  marginLeft: 0,
  marginRight: 0,
  pullOutRadius: 0,
...
});