You must change calculate for X and Y.

X := round(cos(PI * Angle / 180) * Radius / 2 + Radius/2);

Y := round(sin(PI * Angle / 180) * Radius / 2+ Radius/2);

This is because Ellipse( x1,y1,x2,y2 ) draw ellipse bounded on rectangle. (not Ellipse( x1,y1,r1,r2) !!! );

X := round(cos(PI * Angle / 180) * Radius / 2 + Radius/2);

Y := round(sin(PI * Angle / 180) * Radius / 2+ Radius/2);

This is because Ellipse( x1,y1,x2,y2 ) draw ellipse bounded on rectangle. (not Ellipse( x1,y1,r1,r2) !!! );