Battle of the Iron Triangle Battle of the Iron Triangle The Battle of the Iron Triangle took place from 16 May to 20 November 1974, when the People's Army of Vietnam (PAVN) 9th Division captured Rach Bap and An Dien The Army of the Republic of Vietnam (ARVN) regained the lost towns in a series of costly counterattacks. The Iron Triangle was an important strategic location, bounded on the north by the jungle and overgrown rubber plantations of the Long Nguyen Secret Zone, on the west by the Saigon River and on the east by the smaller but unfordable obstacle of the Thi Thinh River.
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: