Triangle Fraternity is a social fraternity, limiting its recruitment of members to male students majoring in engineering, architecture, and the physical, mathematical, biological, and computer sciences. It is the only member of the North-American Interfraternity Conference to limit its membership recruitment to these majors. Triangle Fraternity organized at the University of Illinois at Urbana-Champaign in the fall of 1906 and was incorporated by the state of Illinois on 15 April 1907, which is celebrated each year as Founders' Day. There are currently thirty-three chapters and four colonies of Triangle Fraternity active in the U.S, mostly in the Midwest. The headquarters is located in Plainfield, Indiana in a historic building built as a Carnegie library in 1912. Because Triangle's focus is on men of mostly similar fields of study, it is thought that members are more likely to be able to help each other succeed in their college studies.
Contributions by BigP14, Elipongo, and Rogerd.