// CX, CY: кооординаты центра эллипса
// A, B : полуоси
// Angle - угол поворота в радианах
procedure EllipseAngle(Canvas: TCanvas; CX, CY, A, B: Integer; Angle: Double);
const
DXY = 0.55228475;
var
 X, Y: array[0..12] of Single;
 DX, DY: Single;
 CF, SF: Single;
 Pts: array[0..12] of TPoint;
 i: Integer;
begin
DX := A * DXY;
DY := B * DXY;
X[0] := A;    Y[0] := 0;
X[1] := A;    Y[1] := DY;
X[2] := DX;   Y[2] := B;
X[3] := 0;    Y[3] := B;
X[4] := -DX;  Y[4] := B;
X[5] := -A;   Y[5] := DY;
X[6] := -A;   Y[6] := 0;
X[7] := -A;   Y[7] := -DY;
X[8] := -DX;  Y[8] := -B;
X[9] := 0;    Y[9] := -B;
X[10] := DX;  Y[10] := -B;
X[11] := A;   Y[11] := -DY;
X[12] := A;   Y[12] := 0;
CF := Cos(Angle);
SF := Sin(Angle);
for i := 0 to 12 do begin
  Pts[i].X := Round(X[i] * CF - Y[i] * SF + CX);
  Pts[i].Y := Round(X[i] * SF + Y[i] * CF + CY);
end;
Canvas.PolyBezier(Pts);
end;

procedure TForm2.Button23Click(Sender: TObject);
begin
 EllipseAngle(Canvas, 200, 200, 200, 100, - Pi/4);
end;