Painting and moving a object

ok, so im making a small game to increase my devolpment skills. its basicly Space invaders. my problem is when i make the triangle(Ship) i cant pass in my x and y values example

 Pen mypen =  new Pen (Color.Black);
        mypen.Width = 5;
        g.DrawPolygon(mypen, new PointF[3] {new PointF (400,400),new PointF(500,400),new PointF(450,375)});

but the object moves if i use this to make a circle

// g.FillEllipse( brush, new RectangleF(x -height, y-width, height * 2,width * 2));

so how do i get the triangle to move?