I try to read up on the history of testing and I found an entry that I am having problems researching online. Googeling for Triangle Problems results in geometry hits.
I found an entry on a website.
1973 - Triangle problem (Gruenberger) - In his paper Program Testing: the Historical Perspective - based on the talk held during the Chapel Hill Symposium - Fred Gruenberger introduces the classic triangle problem as a testing idea. Gruenberger takes the problem from the book Computers and Society by Richard Hamming (1972).
What is meant by that? I can not find an online resource for this.