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
Extouch triangle the sides of the reference triangle at the three vertices of the extouch triangle. The area of the extouch triangle, formula_7, is given by: where formula_9, formula_10, formula_11 are the area, radius of the incircle and semiperimeter of the original triangle, and formula_12, formula_13, formula_14 are the side lengths of the original triangle. This is the same area as that of the intouch triangle. Extouch triangle In geometry, the extouch triangle of a triangle is formed by joining the points at which the three excircles touch the triangle. The vertices of the extouch triangle are given in trilinear coordinates by: