var points = new PointF[10]; for (int i = 0; i < 10; ++i) { double p = Math.PI * 2 * i / 10.0; points[i] = new PointF((float)Math.Sin(p), (float)-Math.Cos(p)); if (i % 2 == 1) { points[i].X *= 1 / 2f; //2 / 5f; points[i].Y *= 1 / 2f; //2 / 5f; } }