public void CalculateCentroid()
{
Segment3 LeftRightBimedian = new Segment3(this.LeftSegment.MidPoint, this.RightSegment.MidPoint);
Segment3 TopBottomBimedian = new Segment3(this.BottomSegment.MidPoint, this.TopSegment.MidPoint);
this.Centroid = LeftRightBimedian.Intersect(TopBottomBimedian,1E-4);
}