The Triangle, or Research Triangle, features the metro areas of Durham-Chapel Hill to the west, and Raleigh to the east. The area got its name after the creation of Research Triangle Park.
Created in the 1950s, Research Triangle Park, or RTP, was built to help capitalize off of the number of high-tech companies moving to North Carolina due to the area's universities. RTP is one of the largest research parks in the world and is anchored by the University of North Carolina at Chapel Hill, Duke University and North Carolina State University. When drawing a line between the three institutions it roughly forms the shape of a triangle.
Today RTP is home to more than 200 companies employing more than 50,000 workers.
The Triangle is home to an estimated 1,452,683 (as of 2013) and is one of the fastest growing regions in the country. According to the US Census, the Raleigh metro area is the 14th fastest growing region in the county.
Pro tip: Do not confuse the Triangle with the Triad. The Triad is located west of the Triangle and consists of the North Carolina cities of Greensboro, High Point and Winston-Salem.