<pi:arc cx="100" cy="100" r="50" start="45" sweep="135" stroke="red" fill="none" />
style attribute
orientation="maths"
units="radian"
rotate(90)
rotate(-90)
<pi:pie cx="100" cy="100" r="50" start="45" sweep="135" stroke="red" fill="none" />
fill="none"
start : -90 sweep : 75
start : 0 sweep : 180
start : -45 sweep : 270
start : -45 sweep : -270
some experimentations
some scripting actions
marker-end
fill with gradient
add filter
change fill color
id of pie
animate pie