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
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