I'm not that great at math so there may be an easier way. But it can be done by drawing a line from an x and y coordinate to the radius of the circle you want, then draw lines from that starting point to the next angle (start angle + size) you want to stop at (using "cos" and "sin" to make a circle), then a line from that end angle to the starting x and y coordinate.
This code snip I threw together uses 50 as a size because it makes a nice fat slice. If you change it to 280 you see a pac-man like pie.
Hope this helps.
sync rate 0
sync on
for t=1 to 10000
ink rgb(rnd(255),rnd(255),rnd(255)),0
Pie(rnd(640),rnd(480),rnd(50),rnd(360),50)
sync
next t
` x coordinate, y coordinate, radius, start angle, size of pie
function Pie(x,y,rad,startang,size)
a=startang
c=cos(wrapvalue(a))*rad
s=sin(wrapvalue(a))*rad
line x,y,c+x,s+y
ox=x:oy=y
do
c=cos(wrapvalue(a))*rad
s=sin(wrapvalue(a))*rad
line x+c,y+s,ox,oy
ox=x+c:oy=y+s
inc a
if a>startang+size then exit
loop
line x,y,x+c,y+s
endfunction
