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/computational sciences. It is the only member of the North-American Interfraternity Conference to limit its membership recruitment to these majors.
Triangle Fraternity began to organize at the University of Illinois at Urbana-Champaign in the fall of 1906 and was incorporated by the state of Illinois on April 15, 1907, which is celebrated each year as Founders' Day.
There are currently 30 chapters and 3 colonies of Triangle Fraternity active in the U.S., mostly in the Midwest. The headquarters is located in Plainfield, Indiana in an historic building that was built as a Carnegie library in 1912 .
Because Triangle's focus is on men of mostly similar fields of study, members are more likely to be able to help each other succeed in their college studies. This focus also helps with professional networking later in life, particularly as there are alumni groups scattered throughout the world.