Battle of the Iron Triangle ending a bitter four-month struggle. Following the withdrawal from Base 82 COSVN organized a new corps headquarters in the Tay Ninh- Binh Long region and designated it the 301st Corps. This corps would soon direct the combat operations of the 7th and 9th NVA Divisions, separate regiments, and additional formations already en route from North Vietnam. Meanwhile General Thuần decided to rest the tired troops of the 5th Division and turned his attention to sending his 25th Division to clear out the PAVN bases in the Ho Bo area west of the Iron Triangle. The ARVN defenses around An Dien
Altitude (triangle) the tangential triangle, and the center of similitude of the orthic and tangential triangles, are on the Euler line. Trilinear coordinates for the vertices of the tangential triangle are given by For more information on the orthic triangle, see here. For any triangle with sides and semiperimeter , the altitude from side is given by This follows from combining Heron's formula for the area of a triangle in terms of the sides with the area formula (1/2)×base×height, where the base is taken as side and the height is the altitude from . Consider an arbitrary triangle with sides and with