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
Tangential triangle A reference triangle and its tangential triangle are in perspective, and the axis of perspectivity is the Lemoine axis of the reference triangle. That is, the lines connecting the vertices of the tangential triangle and the corresponding vertices of the reference triangle are concurrent. The center of perspectivity, where these three lines meet, is the symmedian point of the triangle. The tangent lines containing the sides of the tangential triangle are called the exsymmedians of the reference triangle. Any two of these are concurrent with the third symmedian of the reference triangle. The reference triangle's circumcircle, its nine-point circle, its