uses graph,crt;
var g,m:integer;
x,y,ug,c,fy,fx:integer;
tg,rad:real;
begin
randomize;
readln(ug);
c:=0;
initgraph(g,m,'C:\Documents and Settings\angelica\Desktop\bin\i386-win32');
setcolor(blue);
line(720,0,720,480);
line(0,480,720,480);
setcolor(white);
x:=25+random(669);
y:=25+random(429);
repeat
rad:=ug*pi/180;
fx:=x;
fy:=y;
repeat
if (ug<180) then
begin
x:=fx+round(c*cos(rad)/sin(rad));
end
else
begin
x:=fx-round(c*cos(rad)/sin(rad));
end;
if (ug>180) then
begin
y:=fy+c;
end
else
begin
y:=fy-c;
end;
circle(x,y,25);
delay(10);
setcolor(black);
circle(x,y,25);
setcolor(white);
c:=c+1;
until (x=694) or (x=25) or (y=25) or (y=454);
if (y=25) or (y=454) then
begin
ug:=360-ug;
end
else
begin
if (ug<180) then
begin
ug:=180-ug;
end
else
begin
ug:=540-ug;
end;
end;
c:=0;
if x=694 then
begin
x:=693;
end;
if x=25 then
begin
x:=26;
end;
if y=454 then
begin
y:=453;
end;
if y=25 then
begin
y:=26;
end;
until keypressed;
closegraph;
end.
Это шарик отскакивающий от стен.