uses GraphABC;

procedure RLine(x, y, x1, y1: real):=Line(Round(x), Round(y), Round(x1), Round(y1));

procedure Draw(x, y, r, angle: real);
begin
  var ang1 := DegToRad(angle);
  var cx := x + r * Cos(ang1);
  var cy := y + r * Sin(ang1);
  
  var ang2 := Pi / 4;
  
  var ang3 := ang1 - ang2;
  var cx1 := cx + r * Cos(ang3);
  var cy1 := cy + r * Sin(ang3);
  
  var ang4 := ang1 + ang2;
  var cx2 := cx + r * Cos(ang4);
  var cy2 := cy + r * Sin(ang4);
  
  RLine(x, y, cx, cy);
  RLine(cx, cy, cx1, cy1);
  RLine(cx, cy, cx2, cy2);
  
  if r > 1 then
  begin
    r := r * 0.7;
    Draw(cx1, cy1, r, RadToDeg(ang3));
    Draw(cx2, cy2, r, RadToDeg(ang4));
  end;
end;

begin
  FloodFill(1, 1, clBlack);
  
  SetPenColor(clCyan);
  LockDrawing();
  Draw(500, Window.Height - 10, 70, -90);
  Redraw();
end.