текст :
program found;
uses crt,graph;
var
grdr,grmo,x,y:integer;
d:longint;
begin
grdr:=detect;
initgraph(grdr,grmo,'j:\pascal\bgi');
readln;
for x:=1 to 640 do
for y:=1 to 480 do
begin
d:=abs((x-320)*(x-320))+abs((y-240)*(y-240));
if d<50 then putpixel(x,y,white);
end;
readln;
closegraph;
end.