Shelby's Iron Brigade Brigade. The 3rd Brigade Combat Team, 1st Infantry Division was known as the Iron Brigade from its formation in 1917 through World War I, World War II and Vietnam, until some time in the early 2000s when, for reasons that are still unclear, the name was changed to Duke Brigade. The unit crest was an Iron Cross in a triangle, it appears that that was also changed. The 3rd Brigade of the 4th Infantry Division is also known as the Iron Brigade. Its unit crest is similar to the medals issued to veterans of the both Western and the Eastern
Integer triangle then all the other points are at ("x, y") where "x" and "y" range over all positive and negative integers. A lattice triangle is any triangle drawn within a 2D lattice such that all vertices lie on lattice points. By Pick's theorem a lattice triangle has a rational area that either is an integer or has a denominator of 2. If the lattice triangle has integer sides then it is Heronian with integer area. Furthermore, it has been proved that all Heronian triangles can be drawn as lattice triangles. Consequently, an integer triangle is Heronian if and only if it