Quotehttp://gdgraph.com/documentation.htmlOptions for pie graphs
3d
If set to a true value, the pie chart will be drawn with a 3d look. Default: 1.
pie_height
The thickness of the pie when 3d is true. Default: 0.1 x height.
start_angle
The angle at which the first data slice will be displayed, with 0 degrees being "6 o'clock". Default: 0.
suppress_angle
If a pie slice is smaller than this angle (in degrees), a label will not be drawn on it. Default: 0.
label
Print this label below the pie. Default: undef.